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					                          Interview Questions
                         .NET Windows Forms

1. Write a simple Windows Forms MessageBox statement.
2.   System.Windows.Forms.MessageBox.Show ("Hello, Windows Forms");

3. Can you write a class without specifying namespace? Which
   namespace does it belong to by default??
   Yes, you can, then the class belongs to global namespace which has no
   name. For commercial products, naturally, you wouldn‘t want global
4. You are designing a GUI application with a window and several
   widgets on it. The user then resizes the app window and sees a
   lot of grey space, while the widgets stay in place. What‟s the
   problem? One should use anchoring for correct resizing. Otherwise the
   default property of a widget on a form is top-left, so it stays at the same
   location when resized.
5. How can you save the desired properties of Windows Forms
   application? .config files in .NET are supported through the API to allow
   storing and retrieving information. They are nothing more than simple
   XML files, sort of like what .ini files were before for Win32 apps.
6. So how do you retrieve the customized properties of a .NET
   application from XML .config file? Initialize an instance of
   AppSettingsReader class. Call the GetValue method of
   AppSettingsReader class, passing in the name of the property and the
   type expected. Assign the result to the appropriate variable.
7. Can you automate this process? In Visual Studio yes, use Dynamic
   Properties for automatic .config creation, storage and retrieval.
8. My progress bar freezes up and dialog window shows blank,
   when an intensive background process takes over. Yes, you
   should‘ve multi-threaded your GUI, with taskbar and main form being
   one thread, and the background process being the other.
9. What‟s the safest way to deploy a Windows Forms app? Web
   deployment: the user always downloads the latest version of the code;
   the program runs within security sandbox, properly written app will not
   require additional security privileges.
10.       Why is it not a good idea to insert code into
   InitializeComponent method when working with Visual Studio?
   The designer will likely throw it away; most of the code inside
   InitializeComponent is auto-generated.
11.       What‟s the difference between WindowsDefaultLocation
   and WindowsDefaultBounds? WindowsDefaultLocation tells the form
   to start up at a location selected by OS, but with internally specified size.
   WindowsDefaultBounds delegates both size and starting position choices
   to the OS.

                               Page 1 of 165
12.       What‟s the difference between Move and LocationChanged?
   Resize and SizeChanged? Both methods do the same, Move and
   Resize are the names adopted from VB to ease migration to C#.
13.       How would you create a non-rectangular window, let‟s say
   an ellipse? Create a rectangular form, set the TransparencyKey
   property to the same value as BackColor, which will effectively make the
   background of the form transparent. Then set the FormBorderStyle to
   FormBorderStyle.None, which will remove the contour and contents of
   the form.
14.       How do you create a separator in the Menu Designer? A
   hyphen ‗-‘ would do it. Also, an ampersand ‗&\‘ would underline the next
15.       How‟s anchoring different from docking? Anchoring treats the
   component as having the absolute size and adjusts its location relative
   to the parent form. Docking treats the component location as absolute
   and disregards the component size. So if a status bar must always be at
   the bottom no matter what, use docking. If a button should be on the
   top right, but change its position with the form being resized, use

                     Interview Questions
1. What‟s the implicit name of the parameter that gets passed into
   the class‟ set method? Value, and its datatype depends on whatever
   variable we‘re changing.
2. How do you inherit from a class in C#? Place a colon and then the
   name of the base class. Notice that it‘s double colon in C++.
3. Does C# support multiple inheritance? No, use interfaces instead.
4. When you inherit a protected class-level variable, who is it
   available to? Classes in the same namespace.
5. Are private class-level variables inherited? Yes, but they are not
   accessible, so looking at it you can honestly say that they are not
   inherited. But they are.
6. Describe the accessibility modifier protected internal. It‘s available
   to derived classes and classes within the same Assembly (and naturally
   from the base class it‘s declared in).
7. C# provides a default constructor for me. I write a constructor
   that takes a string as a parameter, but want to keep the no
   parameter one. How many constructors should I write? Two. Once
   you write at least one constructor, C# cancels the freebie constructor,
   and now you have to write one yourself, even if there‘s no
   implementation in it.
8. What‟s the top .NET class that everything is derived from?
9. How‟s method overriding different from overloading? When
   overriding, you change the method behavior for a derived class.
   Overloading simply involves having a method with the same name within
   the class.

                             Page 2 of 165
10.       What does the keyword virtual mean in the method
   definition? The method can be over-ridden.
11.       Can you declare the override method static while the
   original method is non-static? No, you can‘t, the signature of the
   virtual method must remain the same, only the keyword virtual is
   changed to keyword override.
12.       Can you override private virtual methods? No, moreover, you
   cannot access private methods in inherited classes, have to be protected
   in the base class to allow any sort of access.
13.       Can you prevent your class from being inherited and
   becoming a base class for some other classes? Yes, that‘s what
   keyword sealed in the class definition is for. The developer trying to
   derive from your class will get a message: cannot inherit from Sealed
   class WhateverBaseClassName. It‘s the same concept as final class in
14.       Can you allow class to be inherited, but prevent the method
   from being over-ridden? Yes, just leave the class public and make the
   method sealed.
15.       What‟s an abstract class? A class that cannot be instantiated. A
   concept in C++ known as pure virtual method. A class that must be
   inherited and have the methods over-ridden. Essentially, it‘s a blueprint
   for a class without any implementation.
16.       When do you absolutely have to declare a class as abstract
   (as opposed to free-willed educated choice or decision based on
   UML diagram)? When at least one of the methods in the class is
   abstract. When the class itself is inherited from an abstract class, but not
   all base abstract methods have been over-ridden.
17.       What‟s an interface class? It‘s an abstract class with public
   abstract methods all of which must be implemented in the inherited
18.       Why can‟t you specify the accessibility modifier for methods
   inside the interface? They all must be public. Therefore, to prevent
   you from getting the false impression that you have any freedom of
   choice, you are not allowed to specify any accessibility, it‘s public by
19.       Can you inherit multiple interfaces?
   Yes, why not.
20.       And if they have conflicting method names? It‘s up to you to
   implement the method inside your own class, so implementation is left
   entirely up to you. This might cause a problem on a higher-level scale if
   similarly named methods from different interfaces expect different data,
   but as far as compiler cares you‘re okay.
21.       What‟s the difference between an interface and abstract
   class? In the interface all methods must be abstract; in the abstract
   class some methods can be concrete. In the interface no accessibility
   modifiers are allowed, which is ok in abstract classes.

                              Page 3 of 165
22.       How can you overload a method? Different parameter data
   types, different number of parameters, different order of parameters.
23.       If a base class has a bunch of overloaded constructors, and
   an inherited class has another bunch of overloaded constructors,
   can you enforce a call from an inherited constructor to an
   arbitrary base constructor? Yes, just place a colon, and then keyword
   base (parameter list to invoke the appropriate constructor) in the
   overloaded constructor definition inside the inherited class.
24.       What‟s the difference between System.String and
   System.StringBuilder classes? System.String is immutable;
   System.StringBuilder was designed with the purpose of having a
   mutable string where a variety of operations can be performed.
25.       What‟s the advantage of using System.Text.StringBuilder
   over System.String? StringBuilder is more efficient in the cases, where
   a lot of manipulation is done to the text. Strings are immutable, so each
   time it‘s being operated on, a new instance is created.
26.       Can you store multiple data types in System.Array? No.
27.       What‟s the difference between the System.Array.CopyTo()
   and System.Array.Clone()? The first one performs a deep copy of the
   array, the second one is shallow.
28.       How can you sort the elements of the array in descending
   order? By calling Sort() and then Reverse() methods.
29.       What‟s the .NET datatype that allows the retrieval of data
   by a unique key? HashTable.
30.       What‟s class SortedList underneath? A sorted HashTable.
31.       Will finally block get executed if the exception had not
   occurred? Yes.
32.       What‟s the C# equivalent of C++ catch (…), which was a
   catch-all statement for any possible exception? A catch block that
   catches the exception of type System.Exception. You can also omit the
   parameter data type in this case and just write catch {}.
33.       Can multiple catch blocks be executed? No, once the proper
   catch code fires off, the control is transferred to the finally block (if there
   are any), and then whatever follows the finally block.
34.       Why is it a bad idea to throw your own exceptions? Well, if at
   that point you know that an error has occurred, then why not write the
   proper code to handle that error instead of passing a new Exception
   object to the catch block? Throwing your own exceptions signifies some
   design flaws in the project.
35.       What‟s a delegate? A delegate object encapsulates a reference
   to a method. In C++ they were referred to as function pointers.
36.       What‟s a multicast delegate? It‘s a delegate that points to and
   eventually fires off several methods.
37.       How‟s the DLL Hell problem solved in .NET? Assembly
   versioning allows the application to specify not only the library it needs
   to run (which was available under Win32), but also the version of the
38.       What are the ways to deploy an assembly? An MSI installer, a
   CAB archive, and XCOPY command.

                               Page 4 of 165
39.       What‟s a satellite assembly? When you write a multilingual or
   multi-cultural application in .NET, and want to distribute the core
   application separately from the localized modules, the localized
   assemblies that modify the core application are called satellite
40.       What namespaces are necessary to create a localized
   application? System.Globalization, System.Resources.
41.       What‟s the difference between // comments, /* */
   comments and /// comments? Single-line, multi-line and XML
   documentation comments.
42.       How do you generate documentation from the C# file
   commented properly with a command-line compiler? Compile it
   with a /doc switch.
43.       What‟s the difference between <c> and <code> XML
   documentation tag? Single line code example and multiple-line code
44.       Is XML case-sensitive? Yes, so <Student> and <student> are
   different elements.
45.       What debugging tools come with the .NET SDK? CorDBG –
   command-line debugger, and DbgCLR – graphic debugger. Visual Studio
   .NET uses the DbgCLR. To use CorDbg, you must compile the original C#
   file using the /debug switch.
46.       What does the This window show in the debugger? It points
   to the object that‘s pointed to by this reference. Object‘s instance data is
47.       What does assert() do? In debug compilation, assert takes in a
   Boolean condition as a parameter, and shows the error dialog if the
   condition is false. The program proceeds without any interruption if the
   condition is true.
48.       What‟s the difference between the Debug class and Trace
   class? Documentation looks the same. Use Debug class for debug
   builds, use Trace class for both debug and release builds.
49.       Why are there five tracing levels in
   System.Diagnostics.TraceSwitcher? The tracing dumps can be quite
   verbose and for some applications that are constantly running you run
   the risk of overloading the machine and the hard drive there. Five levels
   range from None to Verbose, allowing to fine-tune the tracing activities.
50.       Where is the output of TextWriterTraceListener redirected?
   To the Console or a text file depending on the parameter passed to the
51.       How do you debug an ASP.NET Web application? Attach the
   aspnet_wp.exe process to the DbgClr debugger.
52.       What are three test cases you should go through in unit
   testing? Positive test cases (correct data, correct output), negative test
   cases (broken or missing data, proper handling), exception test cases
   (exceptions are thrown and caught properly).
53.       Can you change the value of a variable while debugging a
   C# application? Yes, if you are debugging via Visual Studio.NET, just
   go to Immediate window.

                              Page 5 of 165
54.      Explain the three services model (three-tier application).
   Presentation (UI), business (logic and underlying code) and data (from
   storage or other sources).
55.      What are advantages and disadvantages of Microsoft-
   provided data provider classes in ADO.NET? SQLServer.NET data
   provider is high-speed and robust, but requires SQL Server license
   purchased from Microsoft. OLE-DB.NET is universal for accessing other
   sources, like Oracle, DB2, Microsoft Access and Informix, but it‘s a .NET
   layer on top of OLE layer, so not the fastest thing in the world.
   ODBC.NET is a deprecated layer provided for backward compatibility to
   ODBC engines.
56.      What‟s the role of the DataReader class in ADO.NET
   connections? It returns a read-only dataset from the data source when
   the command is executed.
57.      What is the wildcard character in SQL? Let‟s say you want
   to query database with LIKE for all employees whose name starts
   with La. The wildcard character is %, the proper query with LIKE would
   involve ‗La%‘.
58.      Explain ACID rule of thumb for transactions. Transaction must
   be Atomic (it is one unit of work and does not dependent on previous
   and following transactions), Consistent (data is either committed or roll
   back, no ―in-between‖ case where something has been updated and
   something hasn‘t), Isolated (no transaction sees the intermediate results
   of the current transaction), Durable (the values persist if the data had
   been committed even if the system crashes right after).
59.      What connections does Microsoft SQL Server support?
   Windows Authentication (via Active Directory) and SQL Server
   authentication (via Microsoft SQL Server username and passwords).
60.      Which one is trusted and which one is untrusted? Windows
   Authentication is trusted because the username and password are
   checked with the Active Directory, the SQL Server authentication is
   untrusted, since SQL Server is the only verifier participating in the
61.      Why would you use untrusted verificaion? Web Services
   might use it, as well as non-Windows applications.
62.      What does the parameter Initial Catalog define inside
   Connection String? The database name to connect to.
63.      What‟s the data provider name to connect to Access
   database? Microsoft.Access.
64.      What does Dispose method do with the connection object?
   Deletes it from the memory.
65.      What is a pre-requisite for connection pooling? Multiple
   processes must agree that they will share the same connection, where
   every parameter is the same, including the security settings.

                             Page 6 of 165
                      Interview Questions
                         .NET Remoting

1. What‟s a Windows process? It‘s an application that‘s running and had
   been allocated memory.
2. What‟s typical about a Windows process in regards to memory
   allocation? Each process is allocated its own block of available RAM
   space, no process can access another process‘ code or data. If the
   process crashes, it dies alone without taking the entire OS or a bunch of
   other applications down.
3. Why do you call it a process? What‟s different between process
   and application in .NET, not common computer usage,
   terminology? A process is an instance of a running application. An
   application is an executable on the hard drive or network. There can be
   numerous processes launched of the same application (5 copies of Word
   running), but 1 process can run just 1 application.
4. What distributed process frameworks outside .NET do you know?
   Distributed Computing Environment/Remote Procedure Calls (DEC/RPC),
   Microsoft Distributed Component Object Model (DCOM), Common Object
   Request Broker Architecture (CORBA), and Java Remote Method
   Invocation (RMI).
5. What are possible implementations of distributed applications in
   .NET? .NET Remoting and ASP.NET Web Services. If we talk about the
   Framework Class Library, noteworthy classes are in
   System.Runtime.Remoting and System.Web.Services.
6. When would you use .NET Remoting and when Web services? Use
   remoting for more efficient exchange of information when you control
   both ends of the application. Use Web services for open-protocol-based
   information exchange when you are just a client or a server with the
   other end belonging to someone else.
7. What‟s a proxy of the server object in .NET Remoting? It‘s a fake
   copy of the server object that resides on the client side and behaves as if
   it was the server. It handles the communication between real server
   object and the client object. This process is also known as marshaling.
8. What are remotable objects in .NET Remoting? Remotable objects
   are the objects that can be marshaled across the application domains.
   You can marshal by value, where a deep copy of the object is created
   and then passed to the receiver. You can also marshal by reference,
   where just a reference to an existing object is passed.
9. What are channels in .NET Remoting? Channels represent the
   objects that transfer the other serialized objects from one application
   domain to another and from one computer to another, as well as one
   process to another on the same box. A channel must exist before an
   object can be transferred.
10.       What security measures exist for .NET Remoting in
   System.Runtime.Remoting? None. Security should be taken care of at
   the application level. Cryptography and other security techniques can be
   applied at application or server level.
                              Page 7 of 165
11.       What is a formatter? A formatter is an object that is responsible
   for encoding and serializing data into messages on one end, and
   deserializing and decoding messages into data on the other end.
12.       Choosing between HTTP and TCP for protocols and Binary
   and SOAP for formatters, what are the trade-offs? Binary over TCP
   is the most effiecient, SOAP over HTTP is the most interoperable.
13.       What‟s SingleCall activation mode used for? If the server
   object is instantiated for responding to just one single request, the
   request should be made in SingleCall mode.
14.       What‟s Singleton activation mode? A single object is
   instantiated regardless of the number of clients accessing it. Lifetime of
   this object is determined by lifetime lease.
15.       How do you define the lease of the object? By implementing
   ILease interface when writing the class code.
16.       Can you configure a .NET Remoting object via XML file? Yes,
   via machine.config and application level .config file (or web.config in
   ASP.NET). Application-level XML settings take precedence over
17.       How can you automatically generate interface for the
   remotable object in .NET with Microsoft tools? Use the Soapsuds

                     Interview Questions

 1. Describe the role of inetinfo.exe, aspnet_isapi.dll
    andaspnet_wp.exe in the page loading process. inetinfo.exe is
    theMicrosoft IIS server running, handling ASP.NET requests among
    other things.When an ASP.NET request is received (usually a file with
    .aspx extension),the ISAPI filter aspnet_isapi.dll takes care of it by
    passing the request tothe actual worker process aspnet_wp.exe.
 2. What‟s the difference between Response.Write()
    andResponse.Output.Write()? The latter one allows you to write
 3. What methods are fired during the page load? Init() - when the
    pageis instantiated, Load() - when the page is loaded into server
    memory,PreRender() - the brief moment before the page is displayed
    to the user asHTML, Unload() - when page finishes loading.
 4. Where does the Web page belong in the .NET Framework class
 5. Where do you store the information about the user‟s locale?
 6. What‟s the difference between Codebehind="MyCode.aspx.cs"
    andSrc="MyCode.aspx.cs"? CodeBehind is relevant to Visual
    Studio.NET only.

                              Page 8 of 165
7. What‟s a bubbled event? When you have a complex control, like
   DataGrid, writing an event processing routine for each object (cell,
   button, row, etc.) is quite tedious. The controls can bubble up their
   eventhandlers, allowing the main DataGrid event handler to take care
   of its constituents.
8. Suppose you want a certain ASP.NET function executed on
   MouseOver overa certain button. Where do you add an event
         It‘s the Attributesproperty, the Add function inside that property.
   So btnSubmit.Attributes.Add("onMouseOver","someClientCode();")
9. What data type does the RangeValidator control support?
   Integer,String and Date.
10.      Explain the differences between Server-side and Client-side
   Server-side code runs on the server. Client-side code runs in the
   clients‘ browser.
11.      What type of code (server or client) is found in a Code-
   Behind class?
   Server-side code.
12.      Should validation (did the user enter a real date) occur
   server-side or client-side? Why? Client-side. This reduces an
   additional request to the server to validate the users input.
13.      What does the "EnableViewState" property do? Why would
   I want it on or off?
          It enables the viewstate on the page. It allows the page to save
   the users input on a form.
14.      What is the difference between Server.Transfer and
   Response.Redirect? Why would I choose one over the other?
   Server.Transfer is used to post a form to another page.
   Response.Redirect is used to redirect the user to another page or site.
15.      Can you explain the difference between an ADO.NET
   Dataset and an ADO Recordset?

          A DataSet can represent an entire relational database in memory, complete
           with tables, relations, and views.
          A DataSet is designed to work without any continuing connection to the
           original data source.
          Data in a DataSet is bulk-loaded, rather than being loaded on demand.
          There's no concept of cursor types in a DataSet.
          DataSets have no current record pointer You can use For Each loops to move
           through the data.
          You can store many edits in a DataSet, and write them to the original data
           source in a single operation.
          Though the DataSet is universal, other objects in ADO.NET come in different
           versions for different data sources.

16.    Can you give an example of what might be best suited to
  place in the Application_Start and Session_Start subroutines?
  This is where you can set the specific variables for the Application and
  Session objects.

                               Page 9 of 165
17.     If I‟m developing an application that must accommodate
  multiple security levels though secure login and my ASP.NET
  web application is spanned across three web-servers (using
  round-robin load balancing) what would be the best approach
  to maintain login-in state for the users? Maintain the login state
  security through a database.
18.     Can you explain what inheritance is and an example of
  when you might use it? When you want to inherit (use the
  functionality of) another class. Base Class Employee. A Manager class
  could be derived from the Employee base class.
19.     Whats an assembly? Assemblies are the building blocks of the
  .NET framework. Overview of assemblies from MSDN
20.     Describe the difference between inline and code behind.
  Inline code written along side the html in a page. Code-behind is code
  written in a separate file and referenced by the .aspx page.
21.     Explain what a diffgram is, and a good use for one? The
  DiffGram is one of the two XML formats that you can use to render
  DataSet object contents to XML. For reading database data to an XML
  file to be sent to a Web Service.
22.     Whats MSIL, and why should my developers need an
  appreciation of it if at all? MSIL is the Microsoft Intermediate
  Language. All .NET compatible languages will get converted to MSIL.
23.     Which method do you invoke on the DataAdapter control to
  load your generated dataset with data? The .Fill() method
24.     Can you edit data in the Repeater control? No, it just reads
  the information from its data source
25.     Which template must you provide, in order to display data
  in a Repeater control? ItemTemplate
26.     How can you provide an alternating color scheme in a
  Repeater control? Use the AlternatingItemTemplate
27.     What property must you set, and what method must you
  call in your code, in order to bind the data from some data
  source to the Repeater control? You must set the DataSource
  property and call the DataBind method.
28.     What base class do all Web Forms inherit from? The Page
29.     Name two properties common in every validation control?
  ControlToValidate property and Text property.
30.     What tags do you need to add within the asp:datagrid tags
  to bind columns manually? Set AutoGenerateColumns Property to false on
  the datagrid tag
31.   What tag do you use to add a hyperlink column to the
  DataGrid? <asp:HyperLinkColumn>
32.   What is the transport protocol you use to call a Web
  service? SOAP is the preferred protocol.
33.   True or False: A Web service can only be written in .NET?
34.   What does WSDL stand for? (Web Services Description

                          Page 10 of 165
    35.    Where on the Internet would you look for Web services?
    36.    Which property on a Combo Box do you set with a column
      name, prior to setting the DataSource, to display data in the
      combo box? DataTextField property
    37.    Which control would you use if you needed to make sure
      the values in two different controls matched? CompareValidator
    38.    True or False: To test a Web service you must create a
      windows application or Web application to consume this
      service? False, the webservice comes with a test page and it provides HTTP-GET
       method to test.
    39.     How many classes can a single .NET DLL contain? It can contain many classes.

          C#, .NET, XML, IIS - Interview Questions
    Framework
    OOPS
    C# Language features
    Access specifiers
    Constructor
    ADO.NET
    Asp.Net
    WebService & Remoting
    COM
    XML
    IIS
    Controls
    Programming

1. What is .NET Framework?
   The .NET Framework has two main components: the common language runtime and
   the .NET Framework class library.
   You can think of the runtime as an agent that manages code at execution time,
   providing core services such as memory management, thread management, and
   remoting, while also enforcing strict type safety and other forms of code accuracy that
   ensure security and robustness.
   The class library, is a comprehensive, object-oriented collection of reusable types that
   you can use to develop applications ranging from traditional command-line or graphical
   user interface (GUI) applications to applications based on the latest innovations
   provided by ASP.NET, such as Web Forms and XML Web services.
2. What is CLR, CTS, CLS?
   The .NET Framework provides a runtime environment called the Common Language
   Runtime or CLR (similar to the Java Virtual Machine or JVM in Java), which handles the
   execution of code and provides useful services for the implementation of the program.
   CLR takes care of code management at program execution and provides various
   beneficial services such as memory management, thread management, security
   management, code verification, compilation, and other system services. The managed
   code that targets CLR benefits from useful features such as cross-language integration,
   cross-language exception handling, versioning, enhanced security, deployment support,
   and debugging.
   Common Type System (CTS) describes how types are declared, used and managed in
   the runtime and facilitates cross-language integration, type safety, and high
   performance code execution.

                                   Page 11 of 165
   The CLS is simply a specification that defines the rules to support language integration
   in such a way that programs written in any language, yet can interoperate with one
   another, taking full advantage of inheritance, polymorphism, exceptions, and other
   features. These rules and the specification are documented in the ECMA proposed
   standard document, "Partition I Architecture",
3. What are the new features of Framework 1.1 ?
       1. Native Support for Developing Mobile Web Applications
       2. Enable Execution of Windows Forms Assemblies Originating from the Internet
          Assemblies originating from the Internet zone—for example, Microsoft
          Windows® Forms controls embedded in an Internet-based Web page or
          Windows Forms assemblies hosted on an Internet Web server and loaded either
          through the Web browser or programmatically using the
          System.Reflection.Assembly.LoadFrom() method—now receive sufficient
          permission to execute in a semi-trusted manner. Default security policy has
          been changed so that assemblies assigned by the common language runtime
          (CLR) to the Internet zone code group now receive the constrained permissions
          associated with the Internet permission set. In the .NET Framework 1.0 Service
          Pack 1 and Service Pack 2, such applications received the permissions
          associated with the Nothing permission set and could not execute.
       3. Enable Code Access Security for ASP.NET Applications
          Systems administrators can now use code access security to further lock down
          the permissions granted to ASP.NET Web applications and Web services.
          Although the operating system account under which an application runs imposes
          security restrictions on the application, the code access security system of the
          CLR can enforce additional restrictions on selected application resources based
          on policies specified by systems administrators. You can use this feature in a
          shared server environment (such as an Internet service provider (ISP) hosting
          multiple Web applications on one server) to isolate separate applications from
          one another, as well as with stand-alone servers where you want applications to
          run with the minimum necessary privileges.
       4. Native Support for Communicating with ODBC and Oracle Databases
       5. Unified Programming Model for Smart Client Application Development
          The Microsoft .NET Compact Framework brings the CLR, Windows Forms
          controls, and other .NET Framework features to small devices. The .NET
          Compact Framework supports a large subset of the .NET Framework class
          library optimized for small devices.
       6. Support for IPv6
          The .NET Framework 1.1 supports the emerging update to the Internet Protocol,
          commonly referred to as IP version 6, or simply IPv6. This protocol is designed
          to significantly increase the address space used to identify communication
          endpoints in the Internet to accommodate its ongoing growth.

4. Is .NET a runtime service or a development platform?
   Ans: It's both and actually a lot more. Microsoft .NET includes a new way of delivering
   software and services to businesses and consumers. A part of Microsoft.NET is the .NET
   Frameworks. The .NET frameworks SDK consists of two parts: the .NET common
   language runtime and the .NET class library. In addition, the SDK also includes
   command-line compilers for C#, C++, JScript, and VB. You use these compilers to
   build applications and components. These components require the runtime to execute
   so this is a development platform.
5. What is MSIL, IL?
   When compiling to managed code, the compiler translates your source code into
   Microsoft intermediate language (MSIL), which is a CPU-independent set of instructions
   that can be efficiently converted to native code. MSIL includes instructions for loading,
   storing, initializing, and calling methods on objects, as well as instructions for
   arithmetic and logical operations, control flow, direct memory access, exception
   handling, and other operations. Microsoft intermediate language (MSIL) is a language

                                   Page 12 of 165
      used as the output of a number of compilers and as the input to a just-in-time (JIT)
      compiler. The common language runtime includes a JIT compiler for converting MSIL to
      native code.
6.    Can I write IL programs directly?
      Yes. Peter Drayton posted this simple example to the DOTNET mailing list:
      .assembly MyAssembly {}
      .class MyApp {
        .method static void Main() {
          ldstr    "Hello, IL!"
          call     void System.Console::WriteLine(class System.Object)
      Just put this into a file called, and then run ilasm An exe assembly will
      be generated.
      Can I do things in IL that I can't do in C#?
      Yes. A couple of simple examples are that you can throw exceptions that are not
      derived from System.Exception, and you can have non-zero-based arrays.
7.    What is JIT (just in time)? how it works?
      Before Microsoft intermediate language (MSIL) can be executed, it must be converted
      by a .NET Framework just-in-time (JIT) compiler to native code, which is CPU-specific
      code that runs on the same computer architecture as the JIT compiler.
      Rather than using time and memory to convert all the MSIL in a portable executable
      (PE) file to native code, it converts the MSIL as it is needed during execution and stores
      the resulting native code so that it is accessible for subsequent calls.
      The runtime supplies another mode of compilation called install-time code generation.
      The install-time code generation mode converts MSIL to native code just as the regular
      JIT compiler does, but it converts larger units of code at a time, storing the resulting
      native code for use when the assembly is subsequently loaded and executed.
      As part of compiling MSIL to native code, code must pass a verification process unless
      an administrator has established a security policy that allows code to bypass
      verification. Verification examines MSIL and metadata to find out whether the code can
      be determined to be type safe, which means that it is known to access only the
      memory locations it is authorized to access.
8.    What is strong name?
      A name that consists of an assembly's identity—its simple text name, version number,
      and culture information (if provided)—strengthened by a public key and a digital
      signature generated over the assembly.
9.    What is portable executable (PE)?
      The file format defining the structure that all executable files (EXE) and Dynamic Link
      Libraries (DLL) must use to allow them to be loaded and executed by Windows. PE is
      derived from the Microsoft Common Object File Format (COFF). The EXE and DLL files
      created using the .NET Framework obey the PE/COFF formats and also add additional
      header and data sections to the files that are only used by the CLR. The specification
      for the PE/COFF file formats is available at
10. What is   Event - Delegate? clear syntax for writing a event delegate
    The event keyword lets you specify a delegate that will be called upon the occurrence of
    some "event" in your code. The delegate can have one or more associated methods that will
    be called when your code indicates that the event has occurred. An event in one program
    can be made available to other programs that target the .NET Framework Common
    Language Runtime.
    // keyword_delegate.cs
    // delegate declaration
    delegate void MyDelegate(int i);
11. class Program
12.     {

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13.       public static void Main()
14.       {
15.         TakesADelegate(new MyDelegate(DelegateFunction));
16.       }
17.       public static void TakesADelegate(MyDelegate SomeFunction)
18.       {
19.         SomeFunction(21);
20.       }
21.       public static void DelegateFunction(int i)
22.       {
23.         System.Console.WriteLine("Called by delegate with number: {0}.", i);
24.       }

25. What is Code Access Security (CAS)?
    CAS is the part of the .NET security model that determines whether or not a piece of
    code is allowed to run, and what resources it can use when it is running. For example,
    it is CAS that will prevent a .NET web applet from formatting your hard disk.
    How does CAS work?
    The CAS security policy revolves around two key concepts - code groups and
    permissions. Each .NET assembly is a member of a particular code group, and each
    code group is granted the permissions specified in a named permission set.
    For example, using the default security policy, a control downloaded from a web site
    belongs to the 'Zone - Internet' code group, which adheres to the permissions defined
    by the 'Internet' named permission set. (Naturally the 'Internet' named permission set
    represents a very restrictive range of permissions.)
    Who defines the CAS code groups?
    Microsoft defines some default ones, but you can modify these and even create your
    own. To see the code groups defined on your system, run 'caspol -lg' from the
    command-line. On my syystem it looks like this:
26. Level = Machine
27. Code Groups:
29. 1. All code: Nothing
30.       1.1. Zone - MyComputer: FullTrust
31.         1.1.1. Honor SkipVerification requests: SkipVerification
32.       1.2. Zone - Intranet: LocalIntranet
33.       1.3. Zone - Internet: Internet
34.       1.4. Zone - Untrusted: Nothing
35.       1.5. Zone - Trusted: Internet
       1.6. StrongName -

      Note the hierarchy of code groups - the top of the hierarchy is the most general ('All
      code'), which is then sub-divided into several groups, each of which in turn can be sub-
      divided. Also note that (somewhat counter-intuitively) a sub-group can be associated
      with a more permissive permission set than its parent.
      How do I define my own code group?
      Use caspol. For example, suppose you trust code from and you
      want it have full access to your system, but you want to keep the default restrictions
      for all other internet sites. To achieve this, you would add a new code group as a sub-
      group of the 'Zone - Internet' group, like this:
      caspol -ag 1.3 -site FullTrust
      Now if you run caspol -lg you will see that the new group has been added as group
         1.3. Zone - Internet: Internet
           1.3.1. Site - FullTrust
      Note that the numeric label (1.3.1) is just a caspol invention to make the code groups
      easy to manipulate from the command-line. The underlying runtime never sees it.

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   How do I change the permission set for a code group?
   Use caspol. If you are the machine administrator, you can operate at the 'machine'
   level - which means not only that the changes you make become the default for the
   machine, but also that users cannot change the permissions to be more permissive. If
   you are a normal (non-admin) user you can still modify the permissions, but only to
   make them more restrictive. For example, to allow intranet code to do what it likes you
   might do this:
   caspol -cg 1.2 FullTrust
   Note that because this is more permissive than the default policy (on a standard
   system), you should only do this at the machine level - doing it at the user level will
   have no effect.

   Can I create my own permission set?
   Yes. Use caspol -ap, specifying an XML file containing the permissions in the permission
   set. To save you some time, here is a sample file corresponding to the 'Everything'
   permission set - just edit to suit your needs. When you have edited the sample, add it
   to the range of available permission sets like this:
   caspol -ap samplepermset.xml
   Then, to apply the permission set to a code group, do something like this:
   caspol -cg 1.3 SamplePermSet (By default, 1.3 is the 'Internet' code group)
   I'm having some trouble with CAS. How can I diagnose my problem?
   Caspol has a couple of options that might help. First, you can ask caspol to tell you
   what code group an assembly belongs to, using caspol -rsg. Similarly, you can ask
   what permissions are being applied to a particular assembly using caspol -rsp.

   I can't be bothered with all this CAS stuff. Can I turn it off?
   Yes, as long as you are an administrator. Just run:
   caspol -s off

36. Which namespace is the base class for .net Class library?
    Ans: system.object
37. What are object pooling and connection pooling and difference? Where do we
    set the Min and Max Pool size for connection pooling?
    Object pooling is a COM+ service that enables you to reduce the overhead of creating
    each object from scratch. When an object is activated, it is pulled from the pool. When
    the object is deactivated, it is placed back into the pool to await the next request. You
    can configure object pooling by applying the ObjectPoolingAttribute attribute to a class
    that derives from the System.EnterpriseServices.ServicedComponent class.
    Object pooling lets you control the number of connections you use, as opposed to
    connection pooling, where you control the maximum number reached.
    Following are important differences between object pooling and connection pooling:
         Creation. When using connection pooling, creation is on the same thread, so if
           there is nothing in the pool, a connection is created on your behalf. With object
           pooling, the pool might decide to create a new object. However, if you have
           already reached your maximum, it instead gives you the next available object.
           This is crucial behavior when it takes a long time to create an object, but you do
           not use it for very long.
         Enforcement of minimums and maximums. This is not done in connection
           pooling. The maximum value in object pooling is very important when trying to
           scale your application. You might need to multiplex thousands of requests to
           just a few objects. (TPC/C benchmarks rely on this.)

   COM+ object pooling is identical to what is used in .NET Framework managed SQL
   Client connection pooling. For example, creation is on a different thread and minimums
   and maximums are enforced.

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1. What is Application Domain?
   The primary purpose of the AppDomain is to isolate an application from other
   applications. Win32 processes provide isolation by having distinct memory address
   spaces. This is effective, but it is expensive and doesn't scale well. The .NET runtime
   enforces AppDomain isolation by keeping control over the use of memory - all memory
   in the AppDomain is managed by the .NET runtime, so the runtime can ensure that
   AppDomains do not access each other's memory.
   Objects in different application domains communicate either by transporting copies of
   objects across application domain boundaries, or by using a proxy to exchange
   MarshalByRefObject is the base class for objects that communicate across
   application domain boundaries by exchanging messages using a proxy. Objects that do
   not inherit from MarshalByRefObject are implicitly marshal by value. When a remote
   application references a marshal by value object, a copy of the object is passed across
   application domain boundaries.
   How does an AppDomain get created?
   AppDomains are usually created by hosts. Examples of hosts are the Windows Shell,
   ASP.NET and IE. When you run a .NET application from the command-line, the host is
   the Shell. The Shell creates a new AppDomain for every application.
   AppDomains can also be explicitly created by .NET applications. Here is a C# sample
   which creates an AppDomain, creates an instance of an object inside it, and then
   executes one of the object's methods. Note that you must name the executable
   'appdomaintest.exe' for this code to work as-is.

         using System;
         using System.Runtime.Remoting;

         public class CAppDomainInfo : MarshalByRefObject
                   public string GetAppDomainInfo()
                   return "AppDomain = " + AppDomain.CurrentDomain.FriendlyName;
         public class App
                   public static int Main()
                   AppDomain ad = AppDomain.CreateDomain( "Andy's new domain", null, null
                 ObjectHandle oh = ad.CreateInstance( "appdomaintest", "CAppDomainInfo"
                         CAppDomainInfo adInfo = (CAppDomainInfo)(oh.Unwrap());
                         string info = adInfo.GetAppDomainInfo();
                         Console.WriteLine( "AppDomain info: " + info );
                         return 0;

2. What is serialization in .NET? What are the ways to control serialization?
   Serialization is the process of converting an object into a stream of bytes.
   Deserialization is the opposite process of creating an object from a stream of bytes.
   Serialization/Deserialization is mostly used to transport objects (e.g. during remoting),
   or to persist objects (e.g. to a file or database).Serialization can be defined as the
   process of storing the state of an object to a storage medium. During this process, the
   public and private fields of the object and the name of the class, including the assembly
   containing the class, are converted to a stream of bytes, which is then written to a data
   stream. When the object is subsequently deserialized, an exact clone of the original
   object is created.

                                    Page 16 of 165
          Binary serialization preserves type fidelity, which is useful for preserving the
           state of an object between different invocations of an application. For example,
           you can share an object between different applications by serializing it to the
           clipboard. You can serialize an object to a stream, disk, memory, over the
           network, and so forth. Remoting uses serialization to pass objects "by value"
           from one computer or application domain to another.
          XML serialization serializes only public properties and fields and does not
           preserve type fidelity. This is useful when you want to provide or consume data
           without restricting the application that uses the data. Because XML is an open
           standard, it is an attractive choice for sharing data across the Web. SOAP is an
           open standard, which makes it an attractive choice.

   There are two separate mechanisms provided by the .NET class library - XmlSerializer
   and SoapFormatter/BinaryFormatter. Microsoft uses XmlSerializer for Web Services,
   and uses SoapFormatter/BinaryFormatter for remoting. Both are available for use in
   your own code.
   Why do I get errors when I try to serialize a Hashtable?
   XmlSerializer will refuse to serialize instances of any class that implements IDictionary,
   e.g. Hashtable. SoapFormatter and BinaryFormatter do not have this restriction.

3. What is exception handling?
   When an exception occurs, the system searches for the nearest catch clause that can
   handle the exception, as determined by the run-time type of the exception. First, the
   current method is searched for a lexically enclosing try statement, and the associated
   catch clauses of the try statement are considered in order. If that fails, the method that
   called the current method is searched for a lexically enclosing try statement that
   encloses the point of the call to the current method. This search continues until a catch
   clause is found that can handle the current exception, by naming an exception class
   that is of the same class, or a base class, of the run-time type of the exception being
   thrown. A catch clause that doesn't name an exception class can handle any exception.
   Once a matching catch clause is found, the system prepares to transfer control to the
   first statement of the catch clause. Before execution of the catch clause begins, the
   system first executes, in order, any finally clauses that were associated with try
   statements more nested that than the one that caught the exception.
   Exceptions that occur during destructor execution are worth special mention. If an
   exception occurs during destructor execution, and that exception is not caught, then
   the execution of that destructor is terminated and the destructor of the base class (if
   any) is called. If there is no base class (as in the case of the object type) or if there is
   no base class destructor, then the exception is discarded.
4. What is Assembly?
   Assemblies are the building blocks of .NET Framework applications; they form the
   fundamental unit of deployment, version control, reuse, activation scoping, and
   security permissions. An assembly is a collection of types and resources that are built
   to work together and form a logical unit of functionality. An assembly provides the
   common language runtime with the information it needs to be aware of type
   implementations. To the runtime, a type does not exist outside the context of an
   Assemblies are a fundamental part of programming with the .NET Framework. An
   assembly performs the following functions:
         It contains code that the common language runtime executes. Microsoft
            intermediate language (MSIL) code in a portable executable (PE) file will not be
            executed if it does not have an associated assembly manifest. Note that each
            assembly can have only one entry point (that is, DllMain, WinMain, or Main).
         It forms a security boundary. An assembly is the unit at which permissions are
            requested and granted.
         It forms a type boundary. Every type's identity includes the name of the
            assembly in which it resides. A type called MyType loaded in the scope of one
            assembly is not the same as a type called MyType loaded in the scope of
            another assembly.

                                    Page 17 of 165
          It forms a reference scope boundary. The assembly's manifest contains
           assembly metadata that is used for resolving types and satisfying resource
           requests. It specifies the types and resources that are exposed outside the
           assembly. The manifest also enumerates other assemblies on which it depends.
          It forms a version boundary. The assembly is the smallest versionable unit in
           the common language runtime; all types and resources in the same assembly
           are versioned as a unit. The assembly's manifest describes the version
           dependencies you specify for any dependent assemblies.
          It forms a deployment unit. When an application starts, only the assemblies that
           the application initially calls must be present. Other assemblies, such as
           localization resources or assemblies containing utility classes, can be retrieved
           on demand. This allows applications to be kept simple and thin when first
          It is the unit at which side-by-side execution is supported.

   Assemblies can be static or dynamic. Static assemblies can include .NET Framework
   types (interfaces and classes), as well as resources for the assembly (bitmaps, JPEG
   files, resource files, and so on). Static assemblies are stored on disk in PE files. You can
   also use the .NET Framework to create dynamic assemblies, which are run directly from
   memory and are not saved to disk before execution. You can save dynamic assemblies
   to disk after they have executed.
   There are several ways to create assemblies. You can use development tools, such as
   Visual Studio .NET, that you have used in the past to create .dll or .exe files. You can
   use tools provided in the .NET Framework SDK to create assemblies with modules
   created in other development environments. You can also use common language
   runtime APIs, such as Reflection.Emit, to create dynamic assemblies.

5. What are the contents of assembly?
   In general, a static assembly can consist of four elements:
        The assembly manifest, which contains assembly metadata.
        Type metadata.
        Microsoft intermediate language (MSIL) code that implements the types.
        A set of resources.
6. What are the different types of assemblies?
   Private, Public/Shared, Satellite
7. What is the difference between a private assembly and a shared assembly?
       1. Location and visibility: A private assembly is normally used by a single
          application, and is stored in the application's directory, or a sub-directory
          beneath. A shared assembly is normally stored in the global assembly cache,
          which is a repository of assemblies maintained by the .NET runtime. Shared
          assemblies are usually libraries of code which many applications will find useful,
          e.g. the .NET framework classes.
       2. Versioning: The runtime enforces versioning constraints only on shared
          assemblies, not on private assemblies.

1. What are Satellite Assemblies? How you will create this? How will you get the
   different language strings?
   Satellite assemblies are often used to deploy language-specific resources for an
   application. These language-specific assemblies work in side-by-side execution because
   the application has a separate product ID for each language and installs satellite
   assemblies in a language-specific subdirectory for each language. When uninstalling,
   the application removes only the satellite assemblies associated with a given language
   and .NET Framework version. No core .NET Framework files are removed unless the
   last language for that .NET Framework version is being removed.
   (For example, English and Japanese editions of the .NET Framework version 1.1 share
   the same core files. The Japanese .NET Framework version 1.1 adds satellite
   assemblies with localized resources in a \ja subdirectory. An application that supports
   the .NET Framework version 1.1, regardless of its language, always uses the same core
   runtime files.)

                                   Page 18 of 165
2.   How will u load dynamic assembly? How will create assemblies at run time?
3.   What is Assembly manifest? what all details the assembly manifest will
     Every assembly, whether static or dynamic, contains a collection of data that describes
     how the elements in the assembly relate to each other. The assembly manifest contains
     this assembly metadata. An assembly manifest contains all the metadata needed to
     specify the assembly's version requirements and security identity, and all metadata
     needed to define the scope of the assembly and resolve references to resources and
     classes. The assembly manifest can be stored in either a PE file (an .exe or .dll) with
     Microsoft intermediate language (MSIL) code or in a standalone PE file that contains
     only assembly manifest information.
     It contains Assembly name, Version number, Culture, Strong name information, List of
     all files in the assembly, Type reference information, Information on referenced
4.   Difference between assembly manifest & metadata?
     assembly manifest - An integral part of every assembly that renders the assembly
     self-describing. The assembly manifest contains the assembly's metadata. The manifest
     establishes the assembly identity, specifies the files that make up the assembly
     implementation, specifies the types and resources that make up the assembly, itemizes
     the compile-time dependencies on other assemblies, and specifies the set of
     permissions required for the assembly to run properly. This information is used at run
     time to resolve references, enforce version binding policy, and validate the integrity of
     loaded assemblies. The self-describing nature of assemblies also helps makes zero-
     impact install and XCOPY deployment feasible.
     metadata - Information that describes every element managed by the common
     language runtime: an assembly, loadable file, type, method, and so on. This can
     include information required for debugging and garbage collection, as well as security
     attributes, marshaling data, extended class and member definitions, version binding,
     and other information required by the runtime.
5.   What is Global Assembly Cache (GAC) and what is the purpose of it? (How to
     make an assembly to public? Steps) How more than one version of an
     assembly can keep in same place?
     Each computer where the common language runtime is installed has a machine-wide
     code cache called the global assembly cache. The global assembly cache stores
     assemblies specifically designated to be shared by several applications on the
     computer. You should share assemblies by installing them into the global assembly
     cache only when you need to.
     - Create a strong name using sn.exe tool
     eg: sn -k keyPair.snk
     - with in AssemblyInfo.cs add the generated file name
     eg: [assembly: AssemblyKeyFile("abc.snk")]
     - recompile project, then install it to GAC by either
     drag & drop it to assembly folder (C:\WINDOWS\assembly OR C:\WINNT\assembly)
     (shfusion.dll tool)
     gacutil -i abc.dll
6.   If I have more than one version of one assemblies, then how'll I use old
     version (how/where to specify version number?)in my application?
7.   How to find methods of a assembly file (not using ILDASM)
8.   What is Garbage Collection in .Net? Garbage collection process?
     The process of transitively tracing through all pointers to actively used objects in order
     to locate all objects that can be referenced, and then arranging to reuse any heap
     memory that was not found during this trace. The common language runtime garbage

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    collector also compacts the memory that is in use to reduce the working space needed
    for the heap.
9. What is Reflection in .NET? Namespace? How will you load an assembly which
    is not referenced by current assembly?
    All .NET compilers produce metadata about the types defined in the modules they
    produce. This metadata is packaged along with the module (modules in turn are
    packaged together in assemblies), and can be accessed by a mechanism called
    reflection. The System.Reflection namespace contains classes that can be used to
    interrogate the types for a module/assembly.
    Using reflection to access .NET metadata is very similar to using ITypeLib/ITypeInfo to
    access type library data in COM, and it is used for similar purposes - e.g. determining
    data type sizes for marshaling data across context/process/machine boundaries.
    Reflection can also be used to dynamically invoke methods (see
    System.Type.InvokeMember), or even create types dynamically at run-time (see
10. What is Custom attribute? How to create? If I'm having custom attribute in an
    assembly, how to say that name in the code?
    A: The primary steps to properly design custom attribute classes are as follows:
         a. Applying the AttributeUsageAttribute ([AttributeUsage(AttributeTargets.All,
            Inherited = false, AllowMultiple = true)])
         b. Declaring the attribute. (class public class MyAttribute : System.Attribute { // . .
            . })
         c. Declaring constructors (public MyAttribute(bool myvalue) { this.myvalue =
            myvalue; })
         d. Declaring properties
            public bool MyProperty
            get {return this.myvalue;}
            set {this.myvalue = value;}

   The following example demonstrates the basic way of using reflection to get access to
   custom attributes.
   class MainClass
   public static void Main()
   System.Reflection.MemberInfo info = typeof(MyClass);
   object[] attributes = info.GetCustomAttributes();
   for (int i = 0; i < attributes.Length; i ++)

1. What is the managed and unmanaged code in .net?
   The .NET Framework provides a run-time environment called the Common Language
   Runtime, which manages the execution of code and provides services that make the
   development process easier. Compilers and tools expose the runtime's functionality and
   enable you to write code that benefits from this managed execution environment. Code
   that you develop with a language compiler that targets the runtime is called managed
   code; it benefits from features such as cross-language integration, cross-language
   exception handling, enhanced security, versioning and deployment support, a simplified
   model for component interaction, and debugging and profiling services.
2. How do you create threading in .NET? What is the namespace for that?
3. Serialize and MarshalByRef?

                                    Page 20 of 165
4. using directive vs using statement
   You create an instance in a using statement to ensure that Dispose is called on the
   object when the using statement is exited. A using statement can be exited either
   when the end of the using statement is reached or if, for example, an exception is
   thrown and control leaves the statement block before the end of the statement.
   The using directive has two uses:
        Create an alias for a namespace (a using alias).
        Permit the use of types in a namespace, such that, you do not have to qualify
          the use of a type in that namespace (a using directive).

1. Describe the Managed Execution Process?
   The managed execution process includes the following steps:
      1. Choosing a compiler.
         To obtain the benefits provided by the common language runtime, you must use
         one or more language compilers that target the runtime.
      2. Compiling your code to Microsoft intermediate language (MSIL).
         Compiling translates your source code into MSIL and generates the required
      3. Compiling MSIL to native code.
         At execution time, a just-in-time (JIT) compiler translates the MSIL into native
         code. During this compilation, code must pass a verification process that
         examines the MSIL and metadata to find out whether the code can be
         determined to be type safe.
      4. Executing your code.
         The common language runtime provides the infrastructure that enables
         execution to take place as well as a variety of services that can be used during

1. What is Active Directory? What is the namespace used to access the Microsoft
   Active Directories? What are ADSI Directories?
   Active Directory Service Interfaces (ADSI) is a programmatic interface for Microsoft
   Windows Active Directory. It enables your applications to interact with diverse
   directories on a network, using a single interface. Visual Studio .NET and the .NET
   Framework make it easy to add ADSI functionality with the DirectoryEntry and
   DirectorySearcher components.
   Using ADSI, you can create applications that perform common administrative tasks,
   such as backing up databases, accessing printers, and administering user accounts.
   ADSI makes it possible for you to:
        Log on once to work with diverse directories. The DirectoryEntry component
          class provides username and password properties that can be entered at
          runtime and communicated to the Active Directory object you are binding to.
        Use a single application programming interface (API) to perform tasks on
          multiple directory systems by offering the user a variety of protocols to use. The
          DirectoryServices namespace provides the classes to perform most
          administrative functions.
        Perform "rich querying" on directory systems. ADSI technology allows for
          searching for an object by specifying two query dialects: SQL and LDAP.
        Access and use a single, hierarchical structure for administering and maintaining
          diverse and complicated network configurations by accessing an Active Directory
        Integrate directory information with databases such as SQL Server. The
          DirectoryEntry path may be used as an ADO.NET connection string provided
          that it is using the LDAP provider.

   using System.DirectoryServices;

1. How Garbage Collector (GC) Works?
   The methods in this class influence when an object is garbage collected and when
   resources allocated by an object are released. Properties in this class provide

                                  Page 21 of 165
   information about the total amount of memory available in the system and the age
   category, or generation, of memory allocated to an object. Periodically, the garbage
   collector performs garbage collection to reclaim memory allocated to objects for which
   there are no valid references. Garbage collection happens automatically when a request
   for memory cannot be satisfied using available free memory. Alternatively, an
   application can force garbage collection using the Collect method.
   Garbage collection consists of the following steps:
       1. The garbage collector searches for managed objects that are referenced in
           managed code.
       2. The garbage collector attempts to finalize objects that are not referenced.
       3. The garbage collector frees objects that are not referenced and reclaims their

1. Why do we need to call CG.SupressFinalize?
   Requests that the system not call the finalizer method for the specified object.
   public static void SuppressFinalize(
     object obj
   ); The method removes obj from the set of objects that require finalization. The obj
   parameter is required to be the caller of this method.
   Objects that implement the IDisposable interface can call this method from the
   IDisposable.Dispose method to prevent the garbage collector from calling
   Object.Finalize on an object that does not require it.
2. What is nmake tool?
   The Nmake tool (Nmake.exe) is a 32-bit tool that you use to build projects based on
   commands contained in a .mak file.
   usage : nmake -a all
3. What are Namespaces?
   The namespace keyword is used to declare a scope. This namespace scope lets you
   organize code and gives you a way to create globally-unique types. Even if you do not
   explicitly declare one, a default namespace is created. This unnamed namespace,
   sometimes called the global namespace, is present in every file. Any identifier in the
   global namespace is available for use in a named namespace. Namespaces implicitly
   have public access and this is not modifiable.
4. What is the difference between CONST and READONLY?
   Both are meant for constant values. A const field can only be initialized at the
   declaration of the field. A readonly field can be initialized either at the declaration or in
   a constructor. Therefore, readonly fields can have different values depending on the
   constructor used.
   readonly int b;
   public X()
   public X(string s)
   public X(string s, int i)
   Also, while a const field is a compile-time constant, the readonly field can be used for
   runtime constants, as in the following example:
   public static readonly uint l1 = (uint) DateTime.Now.Ticks; (this can't be possible with
5. What is the difference between ref & out parameters?
   An argument passed to a ref parameter must first be initialized. Compare this to an out
   parameter, whose argument does not have to be explicitly initialized before being
   passed to an out parameter.

                                    Page 22 of 165
6. What is the difference between Array and LinkedList?
7. What is the difference between Array and Arraylist?
    As elements are added to an ArrayList, the capacity is automatically increased as
    required through reallocation. The capacity can be decreased by calling TrimToSize or
    by setting the Capacity property explicitly.
8. What is Jagged Arrays?
    A jagged array is an array whose elements are arrays. The elements of a jagged array
    can be of different dimensions and sizes. A jagged array is sometimes called an "array-
9. What are indexers?
    Indexers are similar to properties, except that the get and set accessors of indexers
    take parameters, while property accessors do not.
10. What is Asynchronous call and how it can be implemented using delegates?
11. How to create events for a control? What is custom events? How to create it?
12. If you want to write your own dot net language, what steps you will u take
13. Describe the difference between inline and code behind - which is best in a
    loosely coupled solution?
14. how dot net compiled code will become platform independent?
15. without modifying source code if we compile again, will it be generated MSIL
16. C++ & C# differences

17. Interop Services?
    The common language runtime provides two mechanisms for interoperating with
    unmanaged code:
        Platform invoke, which enables managed code to call functions exported from an
          unmanaged library.
        COM interop, which enables managed code to interact with COM objects through

   Both platform invoke and COM interop use interop marshaling to accurately move
   method arguments between caller and callee and back, if required.

1. How does u handle this COM components developed in other programming
   languages in .NET?
2. What is RCW (Runtime Callable Wrappers)?
   The common language runtime exposes COM objects through a proxy called the
   runtime callable wrapper (RCW). Although the RCW appears to be an ordinary object to
   .NET clients, its primary function is to marshal calls between a .NET client and a COM
3. What is CCW (COM Callable Wrapper)

   A proxy object generated by the common language runtime so that existing COM
   applications can use managed classes, including .NET Framework classes,

4. How CCW and RCW is working?
5. How will you register com+ services?
   The .NET Framework SDK provides the .NET Framework Services Installation Tool
   (Regsvcs.exe - a command-line tool) to manually register an assembly containing
   serviced components. You can also access these registration features programmatically
   with the System.EnterpriseServicesRegistrationHelper class by creating an instance of
   class RegistrationHelper and using the method InstallAssembly
6. What is use of ContextUtil class?
   ContextUtil is the preferred class to use for obtaining COM+ context information.

                                  Page 23 of 165
7. What is the new three features of COM+ services, which are not there in COM
8. Is the COM architecture same as .Net architecture? What is the difference
    between them?
9. Can we copy a COM dll to GAC folder?
10. What is Pinvoke?
    Platform invoke is a service that enables managed code to call unmanaged functions
    implemented in dynamic-link libraries (DLLs), such as those in the Win32 API. It
    locates and invokes an exported function and marshals its arguments (integers, strings,
    arrays, structures, and so on) across the interoperation boundary as needed.
11. Is it true that COM objects no longer need to be registered on the server?
    Answer: Yes and No. Legacy COM objects still need to be registered on the server
    before they can be used. COM developed using the new .NET Framework will not need
    to be registered. Developers will be able to auto-register these objects just by placing
    them in the 'bin' folder of the application.
12. Can .NET Framework components use the features of Component Services?
    Answer: Yes, you can use the features and functions of Component Services from a
    .NET Framework component.

13. What are the OOPS concepts?
    1) Encapsulation: It is the mechanism that binds together code and data in
    manipulates, and keeps both safe from outside interference and misuse. In short it
    isolates a particular code and data from all other codes and data. A well-defined
    interface controls the access to that particular code and data.
    2) Inheritance: It is the process by which one object acquires the properties of another
    object. This supports the hierarchical classification. Without the use of hierarchies, each
    object would need to define all its characteristics explicitly. However, by use of
    inheritance, an object need only define those qualities that make it unique within its
    class. It can inherit its general attributes from its parent. A new sub-class inherits all of
    the attributes of all of its ancestors.
    3) Polymorphism: It is a feature that allows one interface to be used for general class
    of actions. The specific action is determined by the exact nature of the situation. In
    general polymorphism means "one interface, multiple methods", This means that it is
    possible to design a generic interface to a group of related activities. This helps reduce
    complexity by allowing the same interface to be used to specify a general class of
    action. It is the compiler's job to select the specific action (that is, method) as it applies
    to each situation.
14. What is the difference between a Struct and a Class?
         The struct type is suitable for representing lightweight objects such as Point,
            Rectangle, and Color. Although it is possible to represent a point as a class, a
            struct is more efficient in some scenarios. For example, if you declare an array
            of 1000 Point objects, you will allocate additional memory for referencing each
            object. In this case, the struct is less expensive.
         When you create a struct object using the new operator, it gets created and the
            appropriate constructor is called. Unlike classes, structs can be instantiated
            without using the new operator. If you do not use new, the fields will remain
            unassigned and the object cannot be used until all of the fields are initialized.
         It is an error to declare a default (parameterless) constructor for a struct. A
            default constructor is always provided to initialize the struct members to their
            default values.
         It is an error to initialize an instance field in a struct.
         There is no inheritance for structs as there is for classes. A struct cannot inherit
            from another struct or class, and it cannot be the base of a class. Structs,

                                     Page 24 of 165
           however, inherit from the base class Object. A struct can implement interfaces,
           and it does that exactly as classes do.
        A struct is a value type, while a class is a reference type.
15. Value type & reference types difference? Example from .NET. Integer & struct
    are value types or reference types in .NET?
    Most programming languages provide built-in data types, such as integers and floating-
    point numbers, that are copied when they are passed as arguments (that is, they are
    passed by value). In the .NET Framework, these are called value types. The runtime
    supports two kinds of value types:
        Built-in value types
           The .NET Framework defines built-in value types, such as System.Int32 and
           System.Boolean, which correspond and are identical to primitive data types
           used by programming languages.
        User-defined value types
           Your language will provide ways to define your own value types, which derive
           from System.ValueType. If you want to define a type representing a value that
           is small, such as a complex number (using two floating-point numbers), you
           might choose to define it as a value type because you can pass the value type
           efficiently by value. If the type you are defining would be more efficiently
           passed by reference, you should define it as a class instead.

   Variables of reference types, referred to as objects, store references to the actual data.
   This following are the reference types:

          class
          interface
          delegate

   This following are the built-in reference types:

         object
         string
16. What is Inheritance, Multiple Inheritance, Shared and Repeatable
17. What is Method overloading?
    Method overloading occurs when a class contains two methods with the same name,
    but different signatures.
18. What is Method Overriding? How to override a function in C#?
    Use the override modifier to modify a method, a property, an indexer, or an event. An
    override method provides a new implementation of a member inherited from a base
    class. The method overridden by an override declaration is known as the overridden
    base method. The overridden base method must have the same signature as the
    override method.
    You cannot override a non-virtual or static method. The overridden base method must
    be virtual, abstract, or override.
19. Can we call a base class method without creating instance?
    Its possible If its a static method.
    Its possible by inheriting from that class also.
    Its possible from derived classes using base keyword.
20. You have one base class virtual function how will call that function from
    derived class?
21. class a
22.              {
23.                        public virtual int m()
24.                        {
25.                                  return 1;
26.                        }

                                   Page 25 of 165
27.                 }
28.                 class b:a
29.                 {
30.                          public int j()
31.                          {
32.                                    return m();
33.                          }

34. In which cases you use override and new base?
    Use the new modifier to explicitly hide a member inherited from a base class. To hide
    an inherited member, declare it in the derived class using the same name, and modify
    it with the new modifier.

      C# Language features

35. What are Sealed Classes in C#?
    The sealed modifier is used to prevent derivation from a class. A compile-time error
    occurs if a sealed class is specified as the base class of another class. (A sealed class
    cannot also be an abstract class)
36. What is Polymorphism? How does VB.NET/C# achieve polymorphism?
37. class Token
38.              {
39.                       public string Display()
40.                       {
41.                                 //Implementation goes here
42.                                 return "base";
43.                       }
44.              }
45.              class IdentifierToken:Token
46.              {
47.                       public new string Display() //What is the use of new keyword
48.                       {
49.                                 //Implementation goes here
50.                                 return "derive";
51.                       }
52.              }
53.              static void Method(Token t)
54.              {
55.                       Console.Write(t.Display());
56.              }
57.              public static void Main()
58.              {
59.                       IdentifierToken Variable=new IdentifierToken();
60.                       Method(Variable); //Which Class Method is called here
61.                       Console.ReadLine();
62.              }
63.              For the above code What is the "new" keyword and Which Class Method is
64.                called here

      A: it will call base class Display method

65.     class Token
66.               {
67.                         public virtual string Display()
68.                         {
69.                                   //Implementation goes here
70.                                   return "base";

                                        Page 26 of 165
71.                       }
72.              }
73.              class IdentifierToken:Token
74.              {
75.                       public override string Display() //What is the use of new keyword
76.                       {
77.                                 //Implementation goes here
78.                                 return "derive";
79.                       }
80.              }
81.              static void Method(Token t)
82.              {
83.                       Console.Write(t.Display());
84.              }
85.              public static void Main()
86.              {
87.                       IdentifierToken Variable=new IdentifierToken();
88.                       Method(Variable); //Which Class Method is called here
89.                       Console.ReadLine();
90.              }
91. A: Derive
92. In which Scenario you will go for Interface or Abstract Class?
    Interfaces, like classes, define a set of properties, methods, and events. But unlike
    classes, interfaces do not provide implementation. They are implemented by classes,
    and defined as separate entities from classes. Even though class inheritance allows
    your classes to inherit implementation from a base class, it also forces you to make
    most of your design decisions when the class is first published.
    Abstract classes are useful when creating components because they allow you specify
    an invariant level of functionality in some methods, but leave the implementation of
    other methods until a specific implementation of that class is needed. They also version
    well, because if additional functionality is needed in derived classes, it can be added to
    the base class without breaking code.

                            Interfaces vs. Abstract Classes
   Feature          Interface                     Abstract class
       Multiple     A class may implement         A class may extend only one
     inheritance    several interfaces.           abstract class.
                                                  An abstract class can provide
                    An interface cannot
        Default                                   complete code, default code,
                    provide any code at all,
   implementation                                 and/or just stubs that have to
                    much less default code.
                                                  be overridden.
                    Static final constants only,
                    can use them without
                    qualification in classes that
                    implement the interface. Both instance and static
                    On the other paw, these       constants are possible. Both
      Constants     unqualified names pollute static and instance intialiser
                    the namespace. You can code are also possible to
                    use them and it is not        compute the constants.
                    obvious where they are
                    coming from since the
                    qualification is optional.
                    An interface
                                                  A third party class must be
      Third party implementation may be
                                                  rewritten to extend only from
     convenience added to any existing third
                                                  the abstract class.
                    party class.
                    Interfaces are often used An abstract class defines the
   is-a vs -able or
                    to describe the peripheral core identity of its descendants.
                    abilities of a class, not its If you defined a Dog abstract

                                   Page 27 of 165
              central identity, e.g. an  class then Damamation
              Automobile class might     descendants are Dogs, they are
              implement the Recyclable   not merely dogable.
              interface, which could     Implemented interfaces
              apply to many otherwise    enumerate the general things a
              totally unrelated objects. class can do, not the things a
                                         class is.
                                         You must use the abstract class
                                         as-is for the code base, with all
                                         its attendant baggage, good or
                                         bad. The abstract class author
            You can write a new
                                         has imposed structure on you.
            replacement module for an
                                         Depending on the cleverness of
            interface that contains not
                                         the author of the abstract class,
            one stick of code in
                                         this may be good or bad.
            common with the existing
                                         Another issue that's important is
            implementations. When
                                         what I call "heterogeneous vs.
            you implement the
                                         homogeneous." If
            interface, you start from
                                         implementors/subclasses are
            scratch without any
  Plug-in                                homogeneous, tend towards an
            default implementation.
                                         abstract base class. If they are
            You have to obtain your
                                         heterogeneous, use an interface.
            tools from other classes;
                                         (Now all I have to do is come up
            nothing comes with the
                                         with a good definition of
            interface other than a few
                                         hetero/homogeneous in this
            constants. This gives you
                                         context.) If the various objects
            freedom to implement a
                                         are all of-a-kind, and share a
            radically different internal
                                         common state and behavior,
                                         then tend towards a common
                                         base class. If all they share is a
                                         set of method signatures, then
                                         tend towards an interface.
            If all the various           If the various implementations
            implementations share is are all of a kind and share a
Homogeneity the method signatures,       common status and behavior,
            then an interface works      usually an abstract class works
            best.                        best.
            If your client code talks    Just like an interface, if your
            only in terms of an          client code talks only in terms of
            interface, you can easily    an abstract class, you can easily
            change the concrete          change the concrete
            implementation behind it, implementation behind it, using
            using a factory method.      a factory method.
            Slow, requires extra
            indirection to find the
            corresponding method in
   Speed    the actual class. Modern     Fast
            JVMs are discovering ways
            to reduce this speed
            The constant declarations You can put shared code into an
            in an interface are all      abstract class, where you cannot
            presumed public static       into an interface. If interfaces
            final, so you may leave      want to share code, you will
 Terseness  that part out. You can't     have to write other bubblegum
            call any methods to          to arrange that. You may use
            compute the initial values methods to compute the initial
            of your constants. You       values of your constants and
            need not declare individual variables, both instance and

                             Page 28 of 165
                  methods of an interface     static. You must declare all the
                  abstract. They are all      individual methods of an
                  presumed so.                abstract class abstract.
                  If you add a new method
                  to an interface, you must   If you add a new method to an
                  track down all              abstract class, you have the
       Adding     implementations of that     option of providing a default
    functionality interface in the universe   implementation of it. Then all
                  and provide them with a     existing code will continue to
                  concrete implementation     work without change.
                  of that method.

93. see the code
94. interface ICommon
95.             {
96.                      int getCommon();
97.             }
98.             interface ICommonImplements1:ICommon
99.             {
100.            }
101.            interface ICommonImplements2:ICommon
102.            {
103.            }
104.            public class a:ICommonImplements1,ICommonImplements2
105.            {

   How to implement getCommon method in class a? Are you seeing any problem in the

   public class a:ICommonImplements1,ICommonImplements2
               public int getCommon()
                         return 1;
106. interface IWeather
107.            {
108.                     void display();
109.            }
110.            public class A:IWeather
111.            {
112.                     public void display()
113.                     {
114.                               MessageBox.Show("A");
115.                     }
116.            }
117.            public class B:A
118.            {
119.            }
120.            public class C:B,IWeather
121.            {
122.                     public void display()
123.                     {
124.                               MessageBox.Show("C");
125.                     }
126.            }

                                 Page 29 of 165
127.       When I instantiate C.display(), will it work?
128. interface IPrint
129.           {
130.                    string Display();
131.           }
132.           interface IWrite
133.           {
134.                    string Display();
135.           }
136.           class PrintDoc:IPrint,IWrite
137.           {
138.                    //Here is implementation
139.           }

   how to implement the Display in the class printDoc (How to resolve the naming
   Conflict) A: no naming conflicts

   class PrintDoc:IPrint,IWrite
               public string Display()
                          return "s";
140. interface IList
141.            {
142.              int Count { get; set; }
143.            }
144.            interface ICounter
145.            {
146.              void Count(int i);
147.            }
148.            interface IListCounter: IList, ICounter {}
149.            class C
150.            {
151.              void Test(IListCounter x)
152.              {
153.                 x.Count(1);              // Error
154.                 x.Count = 1;            // Error
155.                 ((IList)x).Count = 1;     // Ok, invokes IList.Count.set
156.                 ((ICounter)x).Count(1);      // Ok, invokes ICounter.Count
157.              }
158.            }
159.       Write one code example for compile time binding and one for run time
   binding? What is early/late binding?
   An object is early bound when it is assigned to a variable declared to be of a specific
   object type. Early bound objects allow the compiler to allocate memory and perform
   other optimizations before an application executes.
   ' Create a variable to hold a new object.
   Dim FS As FileStream
   ' Assign a new object to the variable.
   FS = New FileStream("C:\tmp.txt", FileMode.Open)
   By contrast, an object is late bound when it is assigned to a variable declared to be of
   type Object. Objects of this type can hold references to any object, but lack many of
   the advantages of early-bound objects.
   Dim xlApp As Object
   xlApp = CreateObject("Excel.Application")
160.       Can you explain what inheritance is and an example of when you might
   use it?

                                    Page 30 of 165
161.     How can you write a class to restrict that only one object of this class
   can be created (Singleton class)?

   (Access specifiers)

162.      What are the access-specifiers available in c#?
   Private, Protected, Public, Internal, Protected Internal.
163.      Explain about Protected and protected internal, “internal” access-
   protected - Access is limited to the containing class or types derived from the
   containing class.
   internal - Access is limited to the current assembly.
   protected internal - Access is limited to the current assembly or types derived from the
   containing class.

   (Constructor / Destructor)
164.        Difference between type constructor and instance constructor? What is
   static constructor, when it will be fired? And what is its use?
   (Class constructor method is also known as type constructor or type initializer)
   Instance constructor is executed when a new instance of type is created and the class
   constructor is executed after the type is loaded and before any one of the type
   members is accessed. (It will get executed only 1st time, when we call any static
   methods/fields in the same class.) Class constructors are used for static field
   initialization. Only one class constructor per type is permitted, and it cannot use the
   vararg (variable argument) calling convention.
   A static constructor is used to initialize a class. It is called automatically to initialize the
   class before the first instance is created or any static members are referenced.
165.        What is Private Constructor? and it‟s use? Can you create instance of a
   class which has Private Constructor?
   A: When a class declares only private instance constructors, it is not possible for
   classes outside the program to derive from the class or to directly create instances of
   it. (Except Nested classes)
   Make a constructor private if:
   - You want it to be available only to the class itself. For example, you might have a
   special constructor used only in the implementation of your class' Clone method.
   - You do not want instances of your component to be created. For example, you may
   have a class containing nothing but Shared utility functions, and no instance data.
   Creating instances of the class would waste memory.
166.        I have 3 overloaded constructors in my class. In order to avoid making
   instance of the class do I need to make all constructors to private?
167.        Overloaded constructor will call default constructor internally?
168.        What are virtual destructors?
169.        Destructor and finalize
   Generally in C++ the destructor is called when objects gets destroyed. And one can
   explicitly call the destructors in C++. And also the objects are destroyed in reverse
   order that they are created in. So in C++ you have control over the destructors.
   In C# you can never call them, the reason is one cannot destroy an object. So who has
   the control over the destructor (in C#)? it's the .Net frameworks Garbage Collector
   (GC). GC destroys the objects only when necessary. Some situations of necessity are
   memory is exhausted or user explicitly calls System.GC.Collect() method.
   Points to remember:
   1. Destructors are invoked automatically, and cannot be invoked explicitly.
   2. Destructors cannot be overloaded. Thus, a class can have, at most, one destructor.
   3. Destructors are not inherited. Thus, a class has no destructors other than the one,
   which may be declared in it.
   4. Destructors cannot be used with structs. They are only used with classes.
   5. An instance becomes eligible for destruction when it is no longer possible for any

                                     Page 31 of 165
   code to use the instance.
   6. Execution of the destructor for the instance may occur at any time after the instance
   becomes eligible for destruction.
   7. When an instance is destructed, the destructors in its inheritance chain are called, in
   order, from most derived to least derived.
170.       What is the difference between Finalize and Dispose (Garbage
   Class instances often encapsulate control over resources that are not managed by the
   runtime, such as window handles (HWND), database connections, and so on.
   Therefore, you should provide both an explicit and an implicit way to free those
   resources. Provide implicit control by implementing the protected Finalize Method on an
   object (destructor syntax in C# and the Managed Extensions for C++). The garbage
   collector calls this method at some point after there are no longer any valid references
   to the object.
   In some cases, you might want to provide programmers using an object with the ability
   to explicitly release these external resources before the garbage collector frees the
   object. If an external resource is scarce or expensive, better performance can be
   achieved if the programmer explicitly releases resources when they are no longer being
   used. To provide explicit control, implement the Dispose method provided by the
   IDisposable Interface. The consumer of the object should call this method when it is
   done using the object. Dispose can be called even if other references to the object are
   Note that even when you provide explicit control by way of Dispose, you should
   provide implicit cleanup using the Finalize method. Finalize provides a backup to
   prevent resources from permanently leaking if the programmer fails to call Dispose.
171.       What is close method? How its different from Finalize & Dispose?
172.       What is boxing & unboxing?
173.       What is check/uncheck?
174.       What is the use of base keyword? Tell me a practical example for base
   keyword‟s usage?
175.       What are the different .net tools which u used in projects?
176.       try
   ...//exception occurred here. What'll happen?
   Ans : It will throw exception.
177.       What will do to avoid prior case?
178. try
179. {
180. try
181. {
182. ...
183. }
184. catch
185. {
186. ...
187. //exception occurred here.

                                   Page 32 of 165
188. }
189. finally
190. {
191. ...
192. }
193. }
194. catch
195. {
196. ...
197. }
198. finally
199. {
200. ...
201. try
202. {
203. ...
204. }
205. catch
206. {
207. ...
208. }
209. finally
210. {
211. ..
212. }
213.       Will it go to finally block if there is no exception happened?
   Ans: Yes. The finally block is useful for cleaning up any resources allocated in the try
   block. Control is always passed to the finally block regardless of how the try block
214.       Is goto statement supported in C#? How about Java?
   Gotos are supported in C#to the fullest. In Java goto is a reserved keyword that
   provides absolutely no functionality.
215.       What‟s different about switch statements in C#?
   No fall-throughs allowed. Unlike the C++ switch statement, C# does not support an
   explicit fall through from one case label to another. If you want, you can use goto a
   switch-case, or goto default.
   case 1:
   cost += 25;
   case 2:
   cost += 25;
   goto case 1;

216.      Advantage of ADO.Net?
        ADO.NET Does Not Depend On Continuously Live Connections
        Database Interactions Are Performed Using Data Commands
        Data Can Be Cached in Datasets
        Datasets Are Independent of Data Sources
        Data Is Persisted as XML
        Schemas Define Data Structures
217.      How would u connect to database using .NET?
   SqlConnection nwindConn = new SqlConnection("Data Source=localhost; Integrated
   Security=SSPI;" +
                                "Initial Catalog=northwind");
218.      What are relation objects in dataset and how & where to use them?
   In a DataSet that contains multiple DataTable objects, you can use DataRelation

                                   Page 33 of 165
   objects to relate one table to another, to navigate through the tables, and to return
   child or parent rows from a related table. Adding a DataRelation to a DataSet adds,
   by default, a UniqueConstraint to the parent table and a ForeignKeyConstraint to
   the child table.
   The following code example creates a DataRelation using two DataTable objects in a
   DataSet. Each DataTable contains a column named CustID, which serves as a link
   between the two DataTable objects. The example adds a single DataRelation to the
   Relations collection of the DataSet. The first argument in the example specifies the
   name of the DataRelation being created. The second argument sets the parent
   DataColumn and the third argument sets the child DataColumn.


   private void CreateRelation()
   // Get the DataColumn objects from two DataTable objects in a DataSet.
   DataColumn parentCol;
   DataColumn childCol;
   // Code to get the DataSet not shown here.
   parentCol = DataSet1.Tables["Customers"].Columns["CustID"];
   childCol = DataSet1.Tables["Orders"].Columns["CustID"];
   // Create DataRelation.
   DataRelation relCustOrder;
   relCustOrder = new DataRelation("CustomersOrders", parentCol, childCol);
   // Add the relation to the DataSet.
219.       Difference between OLEDB Provider and SqlClient ?
   Ans: SQLClient .NET classes are highly optimized for the .net / sqlserver combination
   and achieve optimal results. The SqlClient data provider is fast. It's faster than the
   Oracle provider, and faster than accessing database via the OleDb layer. It's faster
   because it accesses the native library (which automatically gives you better
   performance), and it was written with lots of help from the SQL Server team.
220.       What are the different namespaces used in the project to connect the
   database? What data providers available in .net to connect to database?
        System.Data.OleDb – classes that make up the .NET Framework Data Provider
           for OLE DB-compatible data sources. These classes allow you to connect to an
           OLE DB data source, execute commands against the source, and read the
        System.Data.SqlClient – classes that make up the .NET Framework Data
           Provider for SQL Server, which allows you to connect to SQL Server 7.0, execute
           commands, and read results. The System.Data.SqlClient namespace is similar
           to the System.Data.OleDb namespace, but is optimized for access to SQL
           Server 7.0 and later.
        System.Data.Odbc - classes that make up the .NET Framework Data Provider for
           ODBC. These classes allow you to access ODBC data source in the managed
        System.Data.OracleClient - classes that make up the .NET Framework Data
           Provider for Oracle. These classes allow you to access an Oracle data source in
           the managed space.
221.       Difference between DataReader and DataAdapter / DataSet and
   You can use the ADO.NET DataReader to retrieve a read-only, forward-only stream of
   data from a database. Using the DataReader can increase application performance and
   reduce system overhead because only one row at a time is ever in memory.
   After creating an instance of the Command object, you create a DataReader by

                                  Page 34 of 165
   calling Command.ExecuteReader to retrieve rows from a data source, as shown in
   the following example.
   SqlDataReader myReader = myCommand.ExecuteReader();
   You use the Read method of the DataReader object to obtain a row from the results
   of the query.
   while (myReader.Read())
     Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1));
   The DataSet is a memory-resident representation of data that provides a consistent
   relational programming model regardless of the data source. It can be used with
   multiple and differing data sources, used with XML data, or used to manage data local
   to the application. The DataSet represents a complete set of data including related
   tables, constraints, and relationships among the tables. The methods and objects in a
   DataSet are consistent with those in the relational database model. The DataSet can
   also persist and reload its contents as XML and its schema as XML Schema definition
   language (XSD) schema.
   The DataAdapter serves as a bridge between a DataSet and a data source for retrieving
   and saving data. The DataAdapter provides this bridge by mapping Fill, which changes
   the data in the DataSet to match the data in the data source, and Update, which
   changes the data in the data source to match the data in the DataSet. If you are
   connecting to a Microsoft SQL Server database, you can increase overall performance
   by using the SqlDataAdapter along with its associated SqlCommand and SqlConnection.
   For other OLE DB-supported databases, use the DataAdapter with its associated
   OleDbCommand and OleDbConnection objects.
222.       Which method do you invoke on the DataAdapter control to load your
   generated dataset with data?
223.       Explain different methods and Properties of DataReader which you have
   used in your project?
   while (myReader.Read())
     Console.WriteLine("\t{0}\t{1}", myReader.GetInt32(0), myReader.GetString(1));
224.       What happens when we issue Dataset.ReadXml command?
   Reads XML schema and data into the DataSet.
225.       In how many ways we can retrieve table records count? How to find the
   count of records in a dataset?
   foreach(DataTable thisTable in myDataSet.Tables){
   // For each row, print the values of each column.
   foreach(DataRow myRow in thisTable.Rows){
226.       How to check if a datareader is closed or opened?
227.       What happens when u try to update data in a dataset in .NET while the
   record is already deleted in SQL SERVER as backend?
   OR What is concurrency? How will you avoid concurrency when dealing with
   dataset? (One user deleted one row after that another user through his
   dataset was trying to update same row. What will happen? How will you avoid
   the problem?)
228.       How do you merge 2 datasets into the third dataset in a simple manner?
   OR If you are executing these statements in commandObject. "Select * from
   Table1;Select * from Table2” how you will deal result set?
229.       How do you sort a dataset?

                                 Page 35 of 165
230.      If a dataset contains 100 rows, how to fetch rows between 5 and 15
231.      Differences between dataset.clone and dataset.copy?
   Clone - Copies the structure of the DataSet, including all DataTable schemas, relations,
   and constraints. Does not copy any data.
   Copy - Copies both the structure and data for this DataSet.
232.      What is the use of parameter object?
233.      How to generate XML from a dataset and vice versa?
234.      What is method to get XML and schema from Dataset?
   ans: getXML () and get Schema ()
235.      How do u implement locking concept for dataset?

236. and asp – differences?

   Code Render Block                     Code Declaration Block
   Request/Response                      Event Driven
                                         Object Oriented -
                                         Inheritance, overloading..
                                         Exception Handling - Try, Catch,
                                         Down-level Support
                                         User Controls
                                         In-built client side validation
                                         It can span across servers, It can
   Session - weren't transferable across
                                         survive server crashes, can work with
                                         browsers that don't support cookies
                                         its an integral part of OS under the
                                         .net framework. It shares many of
   built on top of the window & IIS, it
                                         the same objects that traditional
   was always a separate entity & its
                                         applications would use, and all .net
   functionality was limited.
                                         objects are available for's
                                         Garbage Collection
                                         Declare variable with datatype
                                         In built graphics support

237.      How ASP and ASP.NET page works? Explain about page life
238.      Order of events in an page? Control Execution Lifecycle?

       Phase         What a control needs to do         Method or event to override
   Initialize     Initialize settings needed during the Init event (OnInit method)
                  lifetime of the incoming Web
   Load view      At the end of this phase, the      LoadViewState method
   state          ViewState property of a control is

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                  automatically populated as
                  described in Maintaining State in a
                  Control. A control can override the
                  default implementation of the
                  LoadViewState method to
                  customize state restoration.
   Process       Process incoming form data and           LoadPostData method (if
   postback data update properties accordingly.           IPostBackDataHandler is
   Load           Perform actions common to all           Load event
                  requests, such as setting up a
                  database query. At this point,          (OnLoad method)
                  server controls in the tree are
                  created and initialized, the state is
                  restored, and form controls reflect
                  client-side data.
   Send postback Raise change events in response to RaisePostDataChangedEvent
   change        state changes between the current method (if
   notifications and previous postbacks.            IPostBackDataHandler is
   Handle         Handle the client-side event that       RaisePostBackEvent method(if
   postback       caused the postback and raise           IPostBackEventHandler is
   events         appropriate events on the server.       implemented)
   Prerender      Perform any updates before the      PreRender event
                  output is rendered. Any changes     (OnPreRender method)
                  made to the state of the control in
                  the prerender phase can be saved,
                  while changes made in the
                  rendering phase are lost.
   Save state     The ViewState property of a            SaveViewState method
                  control is automatically persisted to
                  a string object after this stage. This
                  string object is sent to the client
                  and back as a hidden variable. For
                  improving efficiency, a control can
                  override the SaveViewState
                  method to modify the ViewState
   Render         Generate output to be rendered to       Render method
                  the client.
   Dispose        Perform any final cleanup before  Dispose method
                  the control is torn down.
                  References to expensive resources
                  such as database connections must
                  be released in this phase.
   Unload         Perform any final cleanup before        UnLoad event (On UnLoad
                  the control is torn down. Control       method)
                  authors generally perform cleanup
                  in Dispose and do not handle this

239.      Note To override an EventName event, override the OnEventName method
   (and call base. OnEventName).

240.     What are server controls?
   ASP.NET server controls are components that run on the server and encapsulate user-

                                  Page 37 of 165
   interface and other related functionality. They are used in ASP.NET pages and in
   ASP.NET code-behind classes.
241.       What is the difference between Web User Control and Web Custom
   Custom Controls
   Web custom controls are compiled components that run on the server and that
   encapsulate user-interface and other related functionality into reusable packages. They
   can include all the design-time features of standard ASP.NET server controls, including
   full support for Visual Studio design features such as the Properties window, the visual
   designer, and the Toolbox.
   There are several ways that you can create Web custom controls:
         You can compile a control that combines the functionality of two or more
           existing controls. For example, if you need a control that encapsulates a button
           and a text box, you can create it by compiling the existing controls together.
         If an existing server control almost meets your requirements but lacks some
           required features, you can customize the control by deriving from it and
           overriding its properties, methods, and events.
         If none of the existing Web server controls (or their combinations) meet your
           requirements, you can create a custom control by deriving from one of the base
           control classes. These classes provide all the basic functionality of Web server
           controls, so you can focus on programming the features you need.

   If none of the existing ASP.NET server controls meet the specific requirements of your
   applications, you can create either a Web user control or a Web custom control that
   encapsulates the functionality you need. The main difference between the two controls
   lies in ease of creation vs. ease of use at design time.
   Web user controls are easy to make, but they can be less convenient to use in
   advanced scenarios. You develop Web user controls almost exactly the same way that
   you develop Web Forms pages. Like Web Forms, user controls can be created in the
   visual designer, they can be written with code separated from the HTML, and they can
   handle execution events. However, because Web user controls are compiled
   dynamically at run time they cannot be added to the Toolbox, and they are represented
   by a simple placeholder glyph when added to a page. This makes Web user controls
   harder to use if you are accustomed to full Visual Studio .NET design-time support,
   including the Properties window and Design view previews. Also, the only way to share
   the user control between applications is to put a separate copy in each application,
   which takes more maintenance if you make changes to the control.
   Web custom controls are compiled code, which makes them easier to use but more
   difficult to create; Web custom controls must be authored in code. Once you have
   created the control, however, you can add it to the Toolbox and display it in a visual
   designer with full Properties window support and all the other design-time features of
   ASP.NET server controls. In addition, you can install a single copy of the Web custom
   control in the global assembly cache and share it between applications, which makes
   maintenance easier.

               Web user controls                            Web custom controls
   Easier to create                             Harder to create
   Limited support for consumers who use a      Full visual design tool support for consumers
   visual design tool
   A separate copy of the control is required   Only a single copy of the control is required,
   in each application                          in the global assembly cache
   Cannot be added to the Toolbox in Visual     Can be added to the Toolbox in Visual Studio
   Good for static layout                       Good for dynamic layout


                                  Page 38 of 165
242.      Application and Session Events
   The ASP.NET page framework provides ways for you to work with events that can be
   raised when your application starts or stops or when an individual user's session starts
   or stops:
        Application events are raised for all requests to an application. For example,
          Application_BeginRequest is raised when any Web Forms page or XML Web
          service in your application is requested. This event allows you to initialize
          resources that will be used for each request to the application. A corresponding
          event, Application_EndRequest, provides you with an opportunity to close or
          otherwise dispose of resources used for the request.
        Session events are similar to application events (there is a Session_OnStart
          and a Session_OnEnd event), but are raised with each unique session within
          the application. A session begins when a user requests a page for the first time
          from your application and ends either when your application explicitly closes the
          session or when the session times out.

   You can create handlers for these types of events in the Global.asax file.

243.      Difference between ASP Session and ASP.NET Session? session supports cookie less session & it can span across multiple servers.
244.      What is cookie less session? How it works?
   By default, ASP.NET will store the session state in the same process that processes the
   request, just as ASP does. If cookies are not available, a session can be tracked by
   adding a session identifier to the URL. This can be enabled by setting the following:
   <sessionState cookieless="true" />
245.      How you will handle session when deploying application in more than a
   server? Describe session handling in a webfarm, how does it work and what
   are the limits?
   By default, ASP.NET will store the session state in the same process that processes the
   request, just as ASP does. Additionally, ASP.NET can store session data in an external
   process, which can even reside on another machine. To enable this feature:
        Start the ASP.NET state service, either using the Services snap-in or by
          executing "net start aspnet_state" on the command line. The state service will
          by default listen on port 42424. To change the port, modify the registry key for
          the service:
        Set the mode attribute of the <sessionState> section to "StateServer".
        Configure the stateConnectionString attribute with the values of the machine
          on which you started aspnet_state.

   The following sample assumes that the state service is running on the same machine as
   the Web server ("localhost") and uses the default port (42424):
   <sessionState mode="StateServer" stateConnectionString="tcpip=localhost:42424" />

   Note that if you try the sample above with this setting, you can reset the Web server
   (enter iisreset on the command line) and the session state value will persist.

246.      What method do you use to explicitly kill a users session?
247.      What are the different ways you would consider sending data across
   pages in ASP (i.e between 1.asp to 2.asp)?
   public properties
248.      What is State Management in .Net and how many ways are there to
   maintain a state in .Net? What is view state?
   Web pages are recreated each time the page is posted to the server. In traditional Web

                                  Page 39 of 165
   programming, this would ordinarily mean that all information associated with the page
   and the controls on the page would be lost with each round trip.
   To overcome this inherent limitation of traditional Web programming, the ASP.NET
   page framework includes various options to help you preserve changes — that is, for
   managing state. The page framework includes a facility called view state that
   automatically preserves property values of the page and all the controls on it between
   round trips.
   However, you will probably also have application-specific values that you want to
   preserve. To do so, you can use one of the state management options.
   Client-Based State Management Options:
   View State
   Hidden Form Fields
   Query Strings
   Server-Based State Management Options
   Application State
   Session State
   Database Support
249.       What are the disadvantages of view state / what are the benefits?
   Automatic view-state management is a feature of server controls that enables them to
   repopulate their property values on a round trip (without you having to write any
   code). This feature does impact performance, however, since a server control's view
   state is passed to and from the server in a hidden form field. You should be aware of
   when view state helps you and when it hinders your page's performance.
250.       When maintaining session through Sql server, what is the impact of
   Read and Write operation on Session objects? will performance degrade?
   Maintaining state using database technology is a common practice when storing user-
   specific information where the information store is large. Database storage is
   particularly useful for maintaining long-term state or state that must be preserved even
   if the server must be restarted.
251.       What are the contents of cookie?
252.       How do you create a permanent cookie?
253.       What is ViewState? What does the "EnableViewState" property do? Why
   would I want it on or off?
254.       Explain the differences between Server-side and Client-side code?
   Server side code will process at server side & it will send the result to client. Client side
   code (javascript) will execute only at client side.
255.       Can you give an example of what might be best suited to place in the
   Application_Start and Session_Start subroutines?
256.     Which ASP.NET configuration options are supported in the
  ASP.NET implementation on the shared web hosting platform?
  A: Many of the ASP.NET configuration options are not configurable at
  the site, application or subdirectory level on the shared hosting
  platform. Certain options can affect the security, performance and
  stability of the server and, therefore cannot be changed. The following
  settings are the only ones that can be changed in your site‘s web.config
  file (s):
                                    Page 40 of 165
257.     Briefly describe the role of global.asax?
258.     How can u debug your .net application?
259.     How do u deploy your application?
260.     Where do we store our connection string in application?
261.     Various steps taken to optimize a web based application (caching,
   stored procedure etc.)
262.     How does ASP.NET framework maps client side events to Server side

263.       Security types in ASP/ASP.NET? Different Authentication modes?
264.       How .Net has implemented security for web applications?
265.       How to do Forms authentication in
266.       Explain authentication levels in .net ?
267.       Explain autherization levels in .net ?
268.       What is Role-Based security?
   A role is a named set of principals that have the same privileges with respect to
   security (such as a teller or a manager). A principal can be a member of one or more
   roles. Therefore, applications can use role membership to determine whether a
   principal is authorized to perform a requested action.
269.       How will you do windows authentication and what is the namespace? If
   a user is logged under integrated windows authentication mode, but he is still
   not able to logon, what might be the possible cause for this? In ASP.Net
   application how do you find the name of the logged in person under windows
270.       What are the different authentication modes in the .NET environment?
271. <authentication mode="Windows|Forms|Passport|None">
272.   <forms name="name"
273.                 loginUrl="url"
274.                 protection="All|None|Encryption|Validation"
275.                 timeout="30" path="/" >
276.                 requireSSL="true|false"
277.                 slidingExpiration="true|false">
278.      <credentials passwordFormat="Clear|SHA1|MD5">
279.        <user name="username" password="password"/>
280.      </credentials>
281.              </forms>
282.   <passport redirectUrl="internal"/>
   Attribute Option                                Description
   mode               Controls the default authentication mode for an application.
             Windows Specifies Windows authentication as the default authentication
                     mode. Use this mode when using any form of Microsoft Internet
                     Information Services (IIS) authentication: Basic, Digest,
                     Integrated Windows authentication (NTLM/Kerberos), or
             Forms    Specifies ASP.NET forms-based authentication as the default
                      authentication mode.
             Passport Specifies Microsoft Passport authentication as the default

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                       authentication mode.
             None      Specifies no authentication. Only anonymous users are expected
                       or applications can handle events to provide their own

283.       How do you specify whether your data should be passed as Query string
   and Forms (Mainly about POST and GET)
   Through attribute tag of form tag.
284.       What is the other method, other than GET and POST, in ASP.NET?
285.       What are validator? Name the Validation controls in How do u
   disable them? Will the validators run in server side or client side? How
   do you do Client-side validation in .Net? How to disable validator control by
   client side JavaScript?
   A set of server controls included with ASP.NET that test user input in HTML and Web
   server controls for programmer-defined requirements. Validation controls perform input
   checking in server code. If the user is working with a browser that supports DHTML, the
   validation controls can also perform validation ("EnableClientScript" property set to
   true/false) using client script.
   The following validation controls are available in
   RequiredFieldValidator Control, CompareValidator Control, RangeValidator Control,
   RegularExpressionValidator Control, CustomValidator Control, ValidationSummary
286.       Which two properties are there on every validation control?
   ControlToValidate, ErrorMessage
287.       How do you use css in
   Within the <HEAD> section of an HTML document that will use these styles, add a link
   to this external CSS style sheet that
   follows this form:
   <LINK REL="STYLESHEET" TYPE="text/css" HREF="MyStyles.css">
   MyStyles.css is the name of your external CSS style sheet.
288.       How do you implement postback with a text box? What is postback and
   Make AutoPostBack property to true
289.       How can you debug an ASP page, without touching the code?
290.       What is SQL injection?
   An SQL injection attack "injects" or manipulates SQL code by adding unexpected SQL
   to a query.
   Many web pages take parameters from web user, and make SQL query to the
   database. Take for instance when a user login, web page that user name and password
   and make SQL query to the database to check if a user has valid name and password.
   Username: ' or 1=1 ---
   Password: [Empty]
   This would execute the following query against the users table:
   select count(*) from users where userName='' or 1=1 --' and userPass=''
291.       How can u handle Exceptions in Asp.Net?
292.       How can u handle Un Managed Code Exceptions in ASP.Net?
293. - How to find last error which occurred?
   A: Server.GetLastError();
   Exception LastError;
   String ErrMessage;
   LastError = Server.GetLastError();
   if (LastError != null)
   ErrMessage = LastError.Message;
   ErrMessage = "No Errors";
   Response.Write("Last Error = " + ErrMessage);

                                  Page 42 of 165
294.    How to do Caching in ASP?
   A: <%@ OutputCache Duration="60" VaryByParam="None" %>

   none        One version of page cached (only raw GET)
               n versions of page cached based on query string and/or
               POST body
               n versions of page cached based on value of v1 variable
               in query string or POST body
               n versions of page cached based on value of v1 and v2
               variables in query string or POST body

295.        <%@ OutputCache Duration="60" VaryByParam="none" %>
   <%@ OutputCache Duration="60" VaryByParam="*" %>
   <%@ OutputCache Duration="60" VaryByParam="name;age" %>
   The OutputCache directive supports several other cache varying options
        VaryByHeader - maintain separate cache entry for header string changes
            (UserAgent, UserLanguage, etc.)
        VaryByControl - for user controls, maintain separate cache entry for properties
            of a user control
        VaryByCustom - can specify separate cache entries for browser types and
            version or provide a custom GetVaryByCustomString method in
            HttpApplicationderived class
296.        What is the Global ASA(X) File?
297.        Any alternative to avoid name collisions other then Namespaces.
   A scenario that two namespaces named N1 and N2 are there both having the same
   class say A. now in another class i ve written
   using N1;using N2;
   and i am instantiating class A in this class. Then how will u avoid name collisions?
   Ans: using alias
   Eg: using MyAlias = MyCompany.Proj.Nested;
298.        Which is the namespace used to write error message in event Log File?
299.        What are the page level transaction and class level transaction?
300.        What are different transaction options?
301.        What is the namespace for encryption?
302.        What is the difference between application and cache variables?
303.        What is the difference between control and component?
304.        You ve defined one page_load event in aspx page and same page_load
   event in code behind how will prog run?
305.        Where would you use an IHttpModule, and what are the limitations of
   any approach you might take in implementing one?
306.        Can you edit data in the Repeater control? Which template must you provide, in
   order to display data in a Repeater control? How can you provide an alternating color
   scheme in a Repeater control? What property must you set, and what method must you
   call in your code, in order to bind the data from some data source to the Repeater
307.        What is the use of web.config? Difference between machine.config and
   ASP.NET configuration files are XML-based text files--each named web.config--that can
   appear in any directory on an ASP.NET
   Web application server. Each web.config file applies configuration settings to the
   directory it is located in and to all
   virtual child directories beneath it. Settings in child directories can optionally override
   or modify settings specified in
   parent directories. The root configuration file--
   default configuration settings for the entire machine. ASP.NET configures IIS to prevent

                                   Page 43 of 165
   direct browser access to web.config
   files to ensure that their values cannot become public (attempts to access them will
   cause ASP.NET to return 403: Access
   At run time ASP.NET uses these web.config configuration files to hierarchically compute
   a unique collection of settings for
   each incoming URL target request (these settings are calculated only once and then
   cached across subsequent requests; ASP.NET
   automatically watches for file changes and will invalidate the cache if any of the
   configuration files change).
308.        What is the use of sessionstate tag in the web.config file?
   Configuring session state: Session state features can be configured via the
   <sessionState> section in a web.config file. To double the default timeout of 20
   minutes, you can add the following to the web.config file of an application:
309.        What are the different modes for the sessionstates in the web.config

   Off              Indicates   that   session   state   is   not enabled.
   Inproc           Indicates   that   session   state   is   stored locally.
   StateServer      Indicates   that   session   state   is   stored on a remote server.
   SQLServer        Indicates   that   session   state   is   stored on the SQL Server.

310.     What is smart navigation?
   When a page is requested by an Internet Explorer 5 browser, or later, smart navigation
   enhances the user's experience of the page by performing the following:
       eliminating the flash caused by navigation.
       persisting the scroll position when moving from page to page.
       persisting element focus between navigations.
       retaining only the last page state in the browser's history.

   Smart navigation is best used with ASP.NET pages that require frequent postbacks but
   with visual content that does not change dramatically on return. Consider this carefully
   when deciding whether to set this property to true.
   Set the SmartNavigation attribute to true in the @ Page directive in the .aspx file.
   When the page is requested, the dynamically generated class sets this property.

311.      In what order do the events of an ASPX page execute. As a developer is
   it important to undertsand these events?
312.      How would you get ASP.NET running in Apache web servers - why
   would you even do this?
313.      What tags do you need to add within the asp:datagrid tags to bind
   columns manually
314.      What base class do all Web Forms inherit from?
315.      How can we create pie chart in
316.      Is it possible for me to change my aspx file extension to some other
   Open IIS->Default Website -> Properties
   Select HomeDirectory tab
   Click on configuration button
   Click on add. Enter aspnet_isapi details
   (C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\aspnet_isapi.dll |

                                       Page 44 of 165
   Open machine.config(C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\CONFIG) &
   add new extension under <httpHandlers> tag
   <add verb="*" path="*.santhosh" type="System.Web.UI.PageHandlerFactory"/>
317.     What is AutoEventWireup attribute for ?

318.      What is a WebService and what is the underlying protocol used in
   it?Why Web Services?
   Web Services are applications delivered as a service on the Web. Web services allow for
   programmatic access of business logic over the Web. Web services typically rely on
   XML-based protocols, messages, and interface descriptions for communication and
   access. Web services are designed to be used by other programs or applications rather
   than directly by end user. Programs invoking a Web service are called clients. SOAP
   over HTTP is the most commonly used protocol for invoking Web services.
   There are three main uses of Web services.
      1. Application integration Web services within an intranet are commonly used to
          integrate business applications running on disparate platforms. For example, a
          .NET client running on Windows 2000 can easily invoke a Java Web service
          running on a mainframe or Unix machine to retrieve data from a legacy
      2. Business integration Web services allow trading partners to engage in e-
          business leveraging the existing Internet infrastructure. Organizations can send
          electronic purchase orders to suppliers and receive electronic invoices. Doing e-
          business with Web services means a low barrier to entry because Web services
          can be added to existing applications running on any platform without changing
          legacy code.
      3. Commercial Web services focus on selling content and business services to
          clients over the Internet similar to familiar Web pages. Unlike Web pages,
          commercial Web services target applications not humans as their direct users.
          Continental Airlines exposes flight schedules and status Web services for travel
          Web sites and agencies to use in their applications. Like Web pages, commercial
          Web services are valuable only if they expose a valuable service or content. It
          would be very difficult to get customers to pay you for using a Web service that
          creates business charts with the customers? data. Customers would rather buy
          a charting component (e.g. COM or .NET component) and install it on the same
          machine as their application. On the other hand, it makes sense to sell real-time
          weather information or stock quotes as a Web service. Technology can help you
          add value to your services and explore new markets, but ultimately customers
          pay for contents and/or business services, not for technology

1. Are Web Services a replacement for other distributed computing platforms?
   No. Web Services is just a new way of looking at existing implementation platforms.
2. In a Webservice, need to display 10 rows from a table. So DataReader or
   DataSet is best choice?
   A: WebService will support only DataSet.
3. How to generate WebService proxy? What is SOAP, WSDL, UDDI and the
   concept behind Web Services? What are various components of WSDL? What
   is the use of WSDL.exe utility?
   SOAP is an XML-based messaging framework specifically designed for exchanging
   formatted data across the Internet, for example using request and reply messages or
   sending entire documents. SOAP is simple, easy to use, and completely neutral with
   respect to operating system, programming language, or distributed computing
   After SOAP became available as a mechanism for exchanging XML messages among
   enterprises (or among disparate applications within the same enterprise), a better way
   was needed to describe the messages and how they are exchanged. The Web Services
   Description Language (WSDL) is a particular form of an XML Schema, developed by
   Microsoft and IBM for the purpose of defining the XML message, operation, and

                                  Page 45 of 165
   protocol mapping of a web service accessed using SOAP or other XML protocol. WSDL
   defines web services in terms of "endpoints" that operate on XML messages. The WSDL
   syntax allows both the messages and the operations on the messages to be defined
   abstractly, so they can be mapped to multiple physical implementations. The current
   WSDL spec describes how to map messages and operations to SOAP 1.1, HTTP
   GET/POST, and MIME. WSDL creates web service definitions by mapping a group of
   endpoints into a logical sequence of operations on XML messages. The same XML
   message can be mapped to multiple operations (or services) and bound to one or more
   communications protocols (using "ports").
   The Universal Description, Discovery, and Integration (UDDI) framework defines a data
   model (in XML) and SOAP APIs for registration and searches on business information,
   including the web services a business exposes to the Internet. UDDI is an independent
   consortium of vendors, founded by Microsoft, IBM, and Ariba, for the purpose of
   developing an Internet standard for web service description registration and discovery.
   Microsoft, IBM, and Ariba also are hosting the initial deployment of a UDDI service,
   which is conceptually patterned after DNS (the Internet service that translates URLs
   into TCP addresses). UDDI uses a private agreement profile of SOAP (i.e. UDDI doesn't
   use the SOAP serialization format because it's not well suited to passing complete XML
   documents (it's aimed at RPC style interactions). The main idea is that businesses use
   the SOAP APIs to register themselves with UDDI, and other businesses search UDDI
   when they want to discover a trading partner, for example someone from whom they
   wish to procure sheet metal, bolts, or transistors. The information in UDDI is
   categorized according to industry type and geographical location, allowing UDDI
   consumers to search through lists of potentially matching businesses to find the specific
   one they want to contact. Once a specific business is chosen, another call to UDDI is
   made to obtain the specific contact information for that business. The contact
   information includes a pointer to the target business's WSDL or other XML schema file
   describing the web service that the target business publishes.
4. How to generate proxy class other than .net app and wsdl tool?
   To access an XML Web service from a client application, you first add a Web reference,
   which is a reference to an XML Web service. When you create a Web reference, Visual
   Studio creates an XML Web service proxy class automatically and adds it to your
   project. This proxy class exposes the methods of the XML Web service and handles the
   marshalling of appropriate arguments back and forth between the XML Web service and
   your application. Visual Studio uses the Web Services Description Language (WSDL) to
   create the proxy.
   To generate an XML Web service proxy class:
        From a command prompt, use Wsdl.exe to create a proxy class, specifying (at a
           minimum) the URL to an XML Web service or a service description, or the path
           to a saved service description.
           Wsdl /language:language /protocol:protocol /namespace:myNameSpace
           /username:username /password:password /domain:domain <url or path>

1. What is a proxy in web service? How do I use a proxy server when invoking a
   Web service?

2. asynchronous web service means?
3. What are the events fired when web service called?
4. How will do transaction in Web Services?
5. How does SOAP transport happen and what is the role of HTTP in it? How you
   can access a webservice using soap?
6. What are the different formatters can be used in both? Why?.. binary/soap
7. How you will protect / secure a web service?
   For the most part, things that you do to secure a Web site can be used to secure a Web
   Service. If you need to encrypt the data exchange, you use Secure Sockets Layer (SSL)
   or a Virtual Private Network to keep the bits secure. For authentication, use HTTP Basic
   or Digest authentication with Microsoft® Windows® integration to figure out who the

                                  Page 46 of 165
   these items cannot:
          Parse a SOAP request for valid values
          Authenticate access at the Web Method level (they can authenticate at the Web
           Service level)
        Stop reading a request as soon as it is recognized as invalid

8. How will you expose/publish a webservice?
9. What is disco file?
10. What‟s the attribute for webservice method? What is the namespace for
    creating webservice?

    using System.Web;
    using System.Web.Services;
11. What is Remoting?
    The process of communication between different operating system processes,
    regardless of whether they are on the same computer. The .NET remoting system is an
    architecture designed to simplify communication between objects living in different
    application domains, whether on the same computer or not, and between different
    contexts, whether in the same application domain or not.
12. Difference between web services & remoting?

                    ASP.NET Web Services                .NET Remoting
                                                   Can be accessed over any protocol
   Protocol         Can be accessed only over HTTP (including TCP, HTTP, SMTP and so
                                                     Provide support for both stateful and
   State            Web services work in a stateless
                                                     stateless environments through
   Management       environment
                                                     Singleton and SingleCall objects
                    Web services support only the
                    datatypes defined in the XSD        Using binary communication, .NET
   Type System      type system, limiting the           Remoting can provide support for
                    number of objects that can be       rich type system
                    Web services support
                                                        .NET remoting requires the client be
                    interoperability across
   Interoperability                                     built using .NET, enforcing
                    platforms, and are ideal for
                                                        homogenous environment.
                    heterogeneous environments.
                                                        Can also take advantage of IIS for
                    Highly reliable due to the fact     fault isolation. If IIS is not used,
   Reliability      that Web services are always        application needs to provide
                    hosted in IIS                       plumbing for ensuring the reliability
                                                        of the application.
                    Provides extensibility by
                    allowing us to intercept the        Very extensible by allowing us to
   Extensibility    SOAP messages during the            customize the different components
                    serialization and deserialization   of the .NET remoting framework.
                    Easy-to-create and deploy.          Complex to program.

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13. Though both the .NET Remoting infrastructure and ASP.NET Web services can enable
    cross-process communication, each is designed to benefit a different target audience.
    ASP.NET Web services provide a simple programming model and a wide reach. .NET
    Remoting provides a more complex programming model and has a much narrower
    As explained before, the clear performance advantage provided by TCPChannel-
    remoting should make you think about using this channel whenever you can afford to
    do so. If you can create direct TCP connections from your clients to your server and if
    you need to support only the .NET platform, you should go for this channel. If you are
    going to go cross-platform or you have the requirement of supporting SOAP via HTTP,
    you should definitely go for ASP.NET Web services.
    Both the .NET remoting and ASP.NET Web services are powerful technologies that
    provide a suitable framework for developing distributed applications. It is important to
    understand how both technologies work and then choose the one that is right for your
    application. For applications that require interoperability and must function over public
    networks, Web services are probably the best bet. For those that require
    communications with other .NET components and where performance is a key priority,
    .NET Remoting is the best choice. In short, use Web services when you need to send
    and receive data from different computing platforms, use .NET Remoting when sending
    and receiving data between .NET applications. In some architectural scenarios, you
    might also be able to use.NET Remoting in conjunction with ASP.NET Web services and
    take advantage of the best of both worlds.
    The Key difference between ASP.NET webservices and .NET Remoting is how they
    serialize data into messages and the format they choose for metadata. ASP.NET uses
    XML serializer for serializing or Marshalling. And XSD is used for Metadata. .NET
    Remoting relies on System.Runtime.Serialization.Formatter.Binary and
    System.Runtime.Serialization.SOAPFormatter and relies on .NET CLR Runtime
    assemblies for metadata.
14. Can you pass SOAP messages through remoting?
15. CAO and SAO.
    Client Activated objects are those remote objects whose Lifetime is directly Controlled
    by the client. This is in direct contrast to SAO. Where the server, not the client has
    complete control over the lifetime of the objects.
    Client activated objects are instantiated on the server as soon as the client request the
    object to be created. Unlike as SAO a CAO doesn‘t delay the object creation until the
    first method is called on the object. (In SAO the object is instantiated when the client
    calls the method on the object)
16. singleton and singlecall.
    Singleton types never have more than one instance at any one time. If an instance
    exists, all client requests are serviced by that instance.
    Single Call types always have one instance per client request. The next method
    invocation will be serviced by a different server instance, even if the previous instance
    has not yet been recycled by the system.
17. What is Asynchronous Web Services?
18. Web Client class and its methods?
19. Flow of remoting?
20. What is the use of trace utility?
    Using the SOAP Trace Utility
    The Microsoft® Simple Object Access Protocol (SOAP) Toolkit 2.0 includes a TCP/IP
    trace utility, MSSOAPT.EXE. You use this trace utility to view the SOAP messages sent
    by HTTP between a SOAP client and a service on the server.

   Using the Trace Utility on the Server
   To see all of a service's messages received from and sent to all clients, perform the
   following steps on the server.

       1. On the server, open the Web Services Description Language (WSDL) file.
       2. In the WSDL file, locate the <soap:address> element that corresponds to the
          service and change the location attribute for this element to port 8080. For

                                   Page 48 of 165
           example, if the location attribute specifies
           <http://MyServer/VDir/Service.wsdl> change this attribute to
        3. Run MSSOAPT.exe.
        4. On the File menu, point to New, and either click Formatted Trace (if you
           don't want to see HTTP headers) or click Unformatted Trace (if you do want to
           see HTTP headers).
        5. In the Trace Setup dialog box, click OK to accept the default values.

     Using the Trace Utility on the Client
     To see all messages sent to and received from a service, do the following steps on the

        6. Copy the WSDL file from the server to the client.
        7. Modify location attribute of the <soap:address> element in the local copy of the
            WSDL document to direct the client to localhost:8080 and make a note of the
            current host and port. For example, if the WSDL contains
            <http://MyServer/VDir/Service.wsdl>, change it to
            <http://localhost:8080/VDir/Service.wsdl> and make note of "MyServer".
        8. On the client, run MSSOPT.exe.
        9. On the File menu, point to New, and either click Formatted Trace (if you
            don't want to see HTTP headers) or click Unformatted Trace (if you do want to
            see HTTP headers).
        10. In the Destination host box, enter the host specified in Step 2.
        11. In the Destination port box, enter the port specified in Step 2.
        12. Click OK.


1.  Explain the concept of data island?
2.  How to use XML DOM model on client side using JavaScript.
3.  What are the ways to create a tree view control using XML, XSL & JavaScript?
4.  Questions on XPathNavigator, and the other classes in System.XML
5. What is Use of Template in XSL?
6. What is “Well Formed XML” and “Valid XML”
7. How you will do SubString in XSL
8. Can we do sorting in XSL ? how do you deal sorting columns dynamically in
9. What is “Async” property of XML Means ?
10. What is XPath Query ?
11. Difference Between Element and Node.
12. What is CDATA Section.
13. DOM & SAX parsers explanation and difference
14. What is GetElementbyname method will do?
15. What is selectnode method will give?
16. What is valid xml document? What a well formed xml document?
17. What is the Difference between XmlDocument and XmlDataDocument?
18. Explain what a DiffGram is, and a good use for one?
    A DiffGram is an XML format that is used to identify current and original versions of
    data elements. When sending and retrieving a DataSet from an XML Web service, the
    DiffGram format is implicitly used.
    The DataSet uses the DiffGram format to load and persist its contents, and to serialize
    its contents for transport across a network connection. When a DataSet is written as a
    DiffGram, it populates the DiffGram with all the necessary information to accurately
    recreate the contents, though not the schema, of the DataSet, including column values
    from both the Original and Current row versions, row error information, and row

                                    Page 49 of 165
   DiffGram Format
   The DiffGram format is divided into three sections: the current data, the original (or
   "before") data, and an errors section, as shown in the following example.

   <?xml version="1.0"?>




   The DiffGram format consists of the following blocks of data:

   The name of this element, DataInstance, is used for explanation purposes in this
   documentation. A DataInstance element represents a DataSet or a row of a
   DataTable. Instead of DataInstance, the element would contain the name of the
   DataSet or DataTable. This block of the DiffGram format contains the current data,
   whether it has been modified or not. An element, or row, that has been modified is
   identified with the diffgr:hasChanges annotation.
   This block of the DiffGram format contains the original version of a row. Elements in
   this block are matched to elements in the DataInstance block using the diffgr:id
   This block of the DiffGram format contains error information for a particular row in the
   DataInstance block. Elements in this block are matched to elements in the
   DataInstance block using the diffgr:id annotation.

19. If I replace my Sqlserver with XML files and how about handling the same?
20. Write syntax to serialize class using XML Serializer?

21. In which process does IIS runs (was asking about the EXE file)
    inetinfo.exe is the Microsoft IIS server running, handling ASP.NET requests among
    other things. When an ASP.NET request is received (usually a file with .aspx
    extension), the ISAPI filter aspnet_isapi.dll takes care of it by passing the request to
    the actual worker process aspnet_wp.exe.
22. Where are the IIS log files stored?
23. What are the different IIS authentication modes in IIS 5.0 and Explain?
    Difference between basic and digest authentication modes?
    IIS provides a variety of authentication schemes:
         Anonymous (enabled by default)
         Basic
         Digest
         Integrated Windows authentication (enabled by default)
         Client Certificate Mapping

                                    Page 50 of 165
Anonymous authentication gives users access to the public areas of your Web site
without prompting them for a user name or password. Although listed as an
authentication scheme, it is not technically performing any client authentication
because the client is not required to supply any credentials. Instead, IIS provides
stored credentials to Windows using a special user account, IUSR_machinename. By
default, IIS controls the password for this account. Whether or not IIS controls the
password affects the permissions the anonymous user has. When IIS controls the
password, a sub authentication DLL (iissuba.dll) authenticates the user using a network
logon. The function of this DLL is to validate the password supplied by IIS and to
inform Windows that the password is valid, thereby authenticating the client. However,
it does not actually provide a password to Windows. When IIS does not control the
password, IIS calls the LogonUser() API in Windows and provides the account name,
password and domain name to log on the user using a local logon. After the logon, IIS
caches the security token and impersonates the account. A local logon makes it
possible for the anonymous user to access network resources, whereas a network logon
does not.
Basic Authentication
IIS Basic authentication as an implementation of the basic authentication scheme found
in section 11 of the HTTP 1.0 specification.
As the specification makes clear, this method is, in and of itself, non-secure. The
reason is that Basic authentication assumes a trusted connection between client and
server. Thus, the username and password are transmitted in clear text. More
specifically, they are transmitted using Base64 encoding, which is trivially easy to
decode. This makes Basic authentication the wrong choice to use over a public network
on its own.
Basic Authentication is a long-standing standard supported by nearly all browsers. It
also imposes no special requirements on the server side -- users can authenticate
against any NT domain, or even against accounts on the local machine. With SSL to
shelter the security credentials while they are in transmission, you have an
authentication solution that is both highly secure and quite flexible.
Digest Authentication
The Digest authentication option was added in Windows 2000 and IIS 5.0. Like Basic
authentication, this is an implementation of a technique suggested by Web standards,
namely RFC 2069 (superceded by RFC 2617).
Digest authentication also uses a challenge/response model, but it is much more secure
than Basic authentication (when used without SSL). It achieves this greater security
not by encrypting the secret (the password) before sending it, but rather by following a
different design pattern -- one that does not require the client to transmit the password
over the wire at all.
Instead of sending the password itself, the client transmits a one-way message digest
(a checksum) of the user's password, using (by default) the MD5 algorithm. The server
then fetches the password for that user from a Windows 2000 Domain Controller,
reruns the checksum algorithm on it, and compares the two digests. If they match, the
server knows that the client knows the correct password, even though the password
itself was never sent. (If you have ever wondered what the default ISAPI filter "md5filt"
that is installed with IIS 5.0 is used for, now you know.
Integrated Windows Authentication
Integrated Windows authentication (formerly known as NTLM authentication and
Windows NT Challenge/Response authentication) can use either NTLM or Kerberos V5
authentication and only works with Internet Explorer 2.0 and later.
When Internet Explorer attempts to access a protected resource, IIS sends two WWW-
Authenticate headers, Negotiate and NTLM.

      If Internet Explorer recognizes the Negotiate header, it will choose it because it
       is listed first. When using Negotiate, the browser will return information for both
       NTLM and Kerberos. At the server, IIS will use Kerberos if both the client
       (Internet Explorer 5.0 and later) and server (IIS 5.0 and later) are running

                               Page 51 of 165
           Windows 2000 and later, and both are members of the same domain or trusted
           domains. Otherwise, the server will default to using NTLM.
          If Internet Explorer does not understand Negotiate, it will use NTLM.

   So, which mechanism is used depends upon a negotiation between Internet Explorer
   and IIS.
   When used in conjunction with Kerberos v5 authentication, IIS can delegate security
   credentials among computers running Windows 2000 and later that are trusted and
   configured for delegation. Delegation enables remote access of resources on behalf of
   the delegated user.
   Integrated Windows authentication is the best authentication scheme in an intranet
   environment where users have Windows domain accounts, especially when using
   Kerberos. Integrated Windows authentication, like digest authentication, does not pass
   the user's password across the network. Instead, a hashed value is exchanged.
   Client Certificate Mapping
   A certificate is a digitally signed statement that contains information about an entity
   and the entity's public key, thus binding these two pieces of information together. A
   trusted organization (or entity) called a Certification Authority (CA) issues a certificate
   after the CA verifies that the entity is who it says it is. Certificates can contain different
   types of data. For example, an X.509 certificate includes the format of the certificate,
   the serial number of the certificate, the algorithm used to sign the certificate, the name
   of the CA that issued the certificate, the name and public key of the entity requesting
   the certificate, and the CA's signature. X.509 client certificates simplify authentication
   for larger user bases because they do not rely on a centralized account database. You
   can verify a certificate simply by examining the certificate.

1. How to configure the sites in Web server (IIS)?
2. Advantages in IIS 6.0?
3. IIS Isolation Levels?
   Internet Information Server introduced the notion "Isolation Level", which is also
   present in IIS4 under a different name. IIS5 supports three isolation levels, that you
   can set from the Home Directory tab of the site's Properties dialog:
        Low (IIS Process): ASP pages run in INetInfo.Exe, the main IIS process,
          therefore they are executed in-process. This is the fastest setting, and is the
          default under IIS4. The problem is that if ASP crashes, IIS crashes as well and
          must be restarted (IIS5 has a reliable restart feature that automatically restarts
          a server when a fatal error occurs).
        Medium (Pooled): In this case ASP runs in a different process, which makes
          this setting more reliable: if ASP crashes IIS won't. All the ASP applications at
          the Medium isolation level share the same process, so you can have a web site
          running with just two processes (IIS and ASP process). IIS5 is the first Internet
          Information Server version that supports this setting, which is also the default
          setting when you create an IIS5 application. Note that an ASP application that
          runs at this level is run under COM+, so it's hosted in DLLHOST.EXE (and you
          can see this executable in the Task Manager).
        High (Isolated): Each ASP application runs out-process in its own process
          space, therefore if an ASP application crashes, neither IIS nor any other ASP
          application will be affected. The downside is that you consume more memory
          and resources if the server hosts many ASP applications. Both IIS4 and IIS5
          supports this setting: under IIS4 this process runs inside MTS.EXE, while under
          IIS5 it runs inside DLLHOST.EXE.

   When selecting an isolation level for your ASP application, keep in mind that out-
   process settings - that is, Medium and High - are less efficient than in-process (Low).

                                    Page 52 of 165
   However, out-process communication has been vastly improved under IIS5, and in fact
   IIS5's Medium isolation level often deliver better results than IIS4's Low isolation. In
   practice, you shouldn't set the Low isolation level for an IIS5 application unless you
   really need to serve hundreds pages per second.


4. How will you do Redo and Undo in a TextControl?
5. How to implement DataGrid in .NET? How would u make a combo-box appear
   in one column of a DataGrid? What are the ways to show data grid inside a
   data grid for a master details type of tables? If we write any code for DataGrid
   methods, what is the access specifier used for that methods in the code
   behind file and why?
6. How can we create Tree control in

7. Write a program in C# for checking a given number is PRIME or not.
8. Write a program to find the angle between the hours and minutes in a clock
9. Write a C# program to find the Factorial of n
10. How do I upload a file from my ASP.NET page?
    A: In order to perform file upload in your ASP.NET page, you will need to use two
    classes: the System.Web.UI.HtmlControls.HtmlInputFile class and the
    System.Web.HttpPostedFile class. The HtmlInputFile class represents and HTML input
    control that the user will use on the client side to select a file to upload. The
    HttpPostedFile class represents the uploaded file and is obtained from the PostedFile
    property of the HtmlInputFile class. In order to use the HtmlInputFile control, you need
    to add the enctype attribute to your form tag as follows:
    <form id="upload" method="post" runat="server" enctype="multipart/form-data">
    Also, remember that the /data directory is the only directory with Write permissions
    enabled for the anonymous user. Therefore, you will need to make sure that the your
    code uploads the file to the /data directory or one of its subdirectories.
    Below is a simple example of how to upload a file via an ASP.NET page in C# and
    <%@ Import Namespace="System" %>
    <%@ Import Namespace="System.Web" %>
    <%@ Import Namespace="System.Web.UI.HtmlControls" %>
    <%@ Import Namespace="System.IO" %>
    <%@ Import Namespace="System.Drawing" %>
    <script language="C#" runat="server">
    public void UploadFile(object sender, EventArgs e)
    if (loFile.PostedFile != null)
    string strFileName, strFileNamePath, strFileFolder;
    strFileFolder = Context.Server.MapPath(@"data\");
    strFileName = loFile.PostedFile.FileName;
    strFileName = Path.GetFileName(strFileName);
    strFileNamePath = strFileFolder + strFileName;
    lblFileName.Text = strFileName;
    lblFileLength.Text = loFile.PostedFile.ContentLength.ToString();
    lblFileType.Text = loFile.PostedFile.ContentType;

                                   Page 53 of 165
    pnStatus.Visible = true;
    catch (Exception x)
    Label lblError = new Label();
    lblError.ForeColor = Color.Red;
    lblError.Text = "Exception occurred: " + x.Message;
    lblError.Visible = true;
    <form id="upload_cs" method="post" runat="server" enctype="multipart/form-data">
    <INPUT type="file" id="loFile" runat="server">
    <asp:Button id="btnUpload" runat="server" Text=" Upload "
    <asp:Panel id="pnStatus" runat="server" Visible="False">
    <asp:Label id="lblFileName" Font-Bold="True" Runat="server"></asp:Label>
    <asp:Label id="lblFileLength" Runat="server"></asp:Label> bytes<BR>
    <asp:Label id="lblFileType" Runat="server"></asp:Label>
11. How do I send an email message from my ASP.NET page?
    A: You can use the System.Web.Mail.MailMessage and the System.Web.Mail.SmtpMail
    class to send email in your ASPX pages. Below is a simple example of using this class
    to send mail in C# and VB.NET. In order to send mail through our mail server, you
    would want to make sure to set the static SmtpServer property of the SmtpMail class to
    <%@ Import Namespace="System" %>
    <%@ Import Namespace="System.Web" %>
    <%@ Import Namespace="System.Web.Mail" %>
    <title>Mail Test</title>
    <script language="C#" runat="server">
    private void Page_Load(Object sender, EventArgs e)
    MailMessage mailObj = new MailMessage();
    mailObj.From = "";
    mailObj.To = "";
    mailObj.Subject = "Your Widget Order";
    mailObj.Body = "Your order was processed.";
    mailObj.BodyFormat = MailFormat.Text;
    SmtpMail.SmtpServer = "mail-fwd";
    Response.Write("Mail sent successfully");

                                  Page 54 of 165
        catch (Exception x)
        Response.Write("Your message was not sent: " + x.Message);
        <form id="mail_test" method="post" runat="server">
    12. Write a program to create a user control with name and surname as data
        members and login as method and also the code to call it. (Hint use event
        delegates) Practical Example of Passing an Events to delegates
    13. How can you read 3rd line from a text file?

Areas for study
Assemblies, GAC (how to post private assembly to gac)
.net architecture, MSIL, CTS, CLR
Events, delegates (this is the basics of .net. u have to understand it very well), webform, server controls, user controls, dataset, datareader, dataadapter
remoting, webservice
desktop application - datagrid.

.NET Framework Frequently Asked Questions
Andy McMullan
Last update: 5-Aug-2004

This FAQ tries to answer some commonly asked questions about the
fundamentals of the .NET Framework - topics like assemblies, garbage
collection, security, interop with COM, and remoting. The most commonly-used
parts of the class library are also covered. Other aspects of the .NET
Framework such as ASP.NET, ADO.NET and WinForms are not covered.

This FAQ was inspired by discussions on the DOTNET mailing list. The list has
now been split into several DOTNET-X lists - for details see

Christophe Lauer has translated the FAQ into French - you can find it at



                                       Page 55 of 165
   1. Introduction
       o 1.1 What is .NET?
       o 1.2 Does .NET only apply to people building web-sites?
       o 1.3 When was .NET announced?
       o 1.4 When was the first version of .NET released?
       o 1.5 What tools can I use to develop .NET applications?
       o 1.6 What platforms does the .NET Framework run on?
       o 1.7 What languages does the .NET Framework support?
       o 1.8 Will the .NET Framework go through a standardisation

   2. Basic terminology
       o 2.1 What is the CLR?
       o 2.2 What is the CTS?
       o 2.3 What is the CLS?
       o 2.4 What is IL?
       o 2.5 What is C#?
       o 2.6 What does 'managed' mean in the .NET context?
       o 2.7 What is reflection?

   3. Assemblies
       o 3.1 What is an assembly?
       o 3.2 How can I produce an assembly?
       o 3.3 What is the difference between a private assembly and a
          shared assembly?
       o 3.4 How do assemblies find each other?
       o 3.5 How does assembly versioning work?

   4. Application Domains
       o 4.1 What is an Application Domain?
       o 4.2 How does an AppDomain get created?
       o 4.3 Can I write my own .NET host?

   5. Garbage Collection
       o 5.1 What is garbage collection?
       o 5.2 Is it true that objects don't always get destroyed immediately
          when the last reference goes away?
       o 5.3 Why doesn't the .NET runtime offer deterministic destruction?
       o 5.4 Is the lack of deterministic destruction in .NET a problem?
       o 5.5 Does non-deterministic destruction affect the usage of COM
          objects from managed code?
       o 5.6 I've heard that Finalize methods should be avoided. Should I
          implement Finalize on my class?
       o 5.7 Do I have any control over the garbage collection algorithm?
       o 5.8 How can I find out what the garbage collector is doing?

   6. Serialization
       o 6.1 What is serialization?

                             Page 56 of 165
       o   6.2 Does the .NET Framework have in-built support for
       o   6.3 I want to serialize instances of my class. Should I use
           XmlSerializer, SoapFormatter or BinaryFormatter?
       o   6.4 Can I customise the serialization process?
       o   6.5 Why is XmlSerializer so slow?
       o   6.6 Why do I get errors when I try to serialize a Hashtable?
       o   6.7 XmlSerializer is throwing a generic "There was an error
           reflecting MyClass" error. How do I find out what the problem is?

   7. Attributes
       o 7.1 What are attributes?
       o 7.2 Can I create my own metadata attributes?
       o 7.3 Can I create my own context attributes?

   8. Code Access Security
       o 8.1 What is Code Access Security (CAS)?
       o 8.2 How does CAS work?
       o 8.3 Who defines the CAS code groups?
       o 8.4 How do I define my own code group?
       o 8.5 How do I change the permission set for a code group?
       o 8.6 Can I create my own permission set?
       o 8.7 I'm having some trouble with CAS. How can I diagnose my
       o 8.8 I can't be bothered with all this CAS stuff. Can I turn it off?

   9. Intermediate Language (IL)
       o 9.1 Can I look at the IL for an assembly?
       o 9.2 Can source code be reverse-engineered from IL?
       o 9.3 How can I stop my code being reverse-engineered from IL?
       o 9.4 Can I write IL programs directly?
       o 9.5 Can I do things in IL that I can't do in C#?

   10. Implications for COM
       o 10.1 Is COM dead?
       o 10.2 Is DCOM dead?
       o 10.3 Is MTS/COM+ dead?
       o 10.4 Can I use COM components from .NET programs?
       o 10.5 Can I use .NET components from COM programs?
       o 10.6 Is ATL redundant in the .NET world?

   11. Miscellaneous
       o 11.1 How does .NET remoting work?
       o 11.2 How can I get at the Win32 API from a .NET program?

   12. Class Library
       o 12.1 File I/O
              12.1.1 How do I read from a text file?
              12.1.2 How do I write to a text file?

                               Page 57 of 165
                   12.1.3 How do I read/write binary files?
        o   12.2   Text Processing
                   12.2.1 Are regular expressions supported?
        o   12.3   Internet
                   12.3.1 How do I download a web page?
                   12.3.2 How do I use a proxy?
        o   12.4   XML
                   12.4.1 Is DOM supported?
                   12.4.2 Is SAX supported?
                   12.4.3 Is XPath supported?
        o   12.5   Threading
                   12.5.1 Is multi-threading supported?
                   12.5.2 How do I spawn a thread?
                   12.5.3 How do I stop a thread?
                   12.5.4 How do I use the thread pool?
                   12.5.5 How do I know when my thread pool work item has
                   12.5.6 How do I prevent concurrent access to my data?
        o   12.6   Tracing
                   12.6.1 Is there built-in support for tracing/logging?
                   12.6.2 Can I redirect tracing to a file?
                   12.6.3 Can I customise the trace output?

     13. Resources
         o 13.1 Recommended books
         o 13.2 Internet Resources
         o 13.3 Weblogs
         o 13.4 Sample code & utilities

1. Introduction
1.1 What is .NET?

That's difficult to sum up in a sentence. According to Microsoft, .NET is a
"revolutionary new platform, built on open Internet protocols and standards,
with tools and services that meld computing and communications in new

A more practical definition would be that .NET is a new environment for
developing and running software applications, featuring ease of development
of web-based services, rich standard run-time services available to
components written in a variety of programming languages, and inter-
language and inter-machine interoperability.

Note that when the term ".NET" is used in this FAQ it refers only to the new
.NET runtime and associated technologies. This is sometimes called the ".NET
Framework". This FAQ does NOT cover any of the various other existing and
new products/technologies that Microsoft are attaching the .NET name to (e.g.
SQL Server.NET).

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1.2 Does .NET only apply to people building web-sites?

No. If you write any Windows software (using ATL/COM, MFC, VB, or even raw
Win32), .NET may offer a viable alternative (or addition) to the way you do
things currently. Of course, if you do develop web sites, then .NET has lots to
interest you - not least ASP.NET.

1.3 When was .NET announced?

Bill Gates delivered a keynote at Forum 2000, held June 22, 2000, outlining
the .NET 'vision'. The July 2000 PDC had a number of sessions on .NET
technology, and delegates were given CDs containing a pre-release version of
the .NET framework/SDK and Visual Studio.NET.

1.4 When was the first version of .NET released?

The final version of the 1.0 SDK and runtime was made publicly available
around 6pm PST on 15-Jan-2002. At the same time, the final version of Visual
Studio.NET was made available to MSDN subscribers.

1.5 What tools can I use to develop .NET applications?

There are a number of tools, described here in ascending order of cost:

     .NET Framework SDK: The SDK is free and includes command-line
      compilers for C++, C#, and VB.NET and various other utilities to aid
     ASP.NET Web Matrix: This is a free ASP.NET development environment
      from Microsoft. As well as a GUI development environment, the
      download includes a simple web server that can be used instead of IIS to
      host ASP.NET apps. This opens up ASP.NET development to users of
      Windows XP Home Edition, which cannot run IIS.
     Microsoft Visual C# .NET Standard 2003: This is a cheap (around $100)
      version of Visual Studio limited to one language and also with limited
      wizard support. For example, there's no wizard support for class libraries
      or custom UI controls. Useful for beginners to learn with, or for savvy
      developers who can work around the deficiencies in the supplied wizards.
      As well as C#, there are VB.NET and C++ versions.
     Microsoft Visual Studio.NET Professional 2003: If you have a license for
      Visual Studio 6.0, you can get the upgrade. You can also upgrade from
      VS.NET 2002 for a token $30. Visual Studio.NET includes support for all
      the MS languages (C#, C++, VB.NET) and has extensive wizard support.

At the top end of the price spectrum are the Visual Studio.NET 2003 Enterprise
and Enterprise Architect editions. These offer extra features such as Visual
Sourcesafe (version control), and performance and analysis tools. Check out
the Visual Studio.NET Feature Comparison at

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1.6 What platforms does the .NET Framework run on?

The runtime supports Windows XP, Windows 2000, NT4 SP6a and Windows
ME/98. Windows 95 is not supported. Some parts of the framework do not
work on all platforms - for example, ASP.NET is only supported on Windows XP
and Windows 2000. Windows 98/ME cannot be used for development.

IIS is not supported on Windows XP Home Edition, and so cannot be used to
host ASP.NET. However, the ASP.NET Web Matrix web server does run on XP

The Mono project is attempting to implement the .NET framework on Linux.

1.7 What languages does the .NET Framework support?

MS provides compilers for C#, C++, VB and JScript. Other vendors have
announced that they intend to develop .NET compilers for languages such as
COBOL, Eiffel, Perl, Smalltalk and Python.

1.8 Will the .NET Framework go through a standardisation

From "On December 13, 2001, the
ECMA General Assembly ratified the C# and common language infrastructure
(CLI) specifications into international standards. The ECMA standards will be
known as ECMA-334 (C#) and ECMA-335 (the CLI)."

2. Basic terminology
2.1 What is the CLR?

CLR = Common Language Runtime. The CLR is a set of standard resources
that (in theory) any .NET program can take advantage of, regardless of
programming language. Robert Schmidt (Microsoft) lists the following CLR
resources in his MSDN PDC# article:

     Object-oriented programming model (inheritance, polymorphism,
      exception handling, garbage collection)
     Security model
     Type system
     All .NET base classes
     Many .NET framework classes
     Development, debugging, and profiling tools
     Execution and code management
     IL-to-native translators and optimizers

What this means is that in the .NET world, different programming languages
will be more equal in capability than they have ever been before, although
clearly not all languages will support all CLR services.
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2.2 What is the CTS?

CTS = Common Type System. This is the range of types that the .NET runtime
understands, and therefore that .NET applications can use. However note that
not all .NET languages will support all the types in the CTS. The CTS is a
superset of the CLS.

2.3 What is the CLS?

CLS = Common Language Specification. This is a subset of the CTS which all
.NET languages are expected to support. The idea is that any program which
uses CLS-compliant types can interoperate with any .NET program written in
any language.

In theory this allows very tight interop between different .NET languages - for
example allowing a C# class to inherit from a VB class.

2.4 What is IL?

IL = Intermediate Language. Also known as MSIL (Microsoft Intermediate
Language) or CIL (Common Intermediate Language). All .NET source code (of
any language) is compiled to IL. The IL is then converted to machine code at
the point where the software is installed, or at run-time by a Just-In-Time
(JIT) compiler.

2.5 What is C#?

C# is a new language designed by Microsoft to work with the .NET framework.
In their "Introduction to C#" whitepaper, Microsoft describe C# as follows:

"C# is a simple, modern, object oriented, and type-safe programming
language derived from C and C++. C# (pronounced ―C sharp‖) is firmly
planted in the C and C++ family tree of languages, and will immediately be
familiar to C and C++ programmers. C# aims to combine the high productivity
of Visual Basic and the raw power of C++."

Substitute 'Java' for 'C#' in the quote above, and you'll see that the statement
still works pretty well :-).

If you are a C++ programmer, you might like to check out my C# FAQ.

2.6 What does 'managed' mean in the .NET context?

The term 'managed' is the cause of much confusion. It is used in various
places within .NET, meaning slightly different things.

Managed code: The .NET framework provides several core run-time services to
the programs that run within it - for example exception handling and security.
For these services to work, the code must provide a minimum level of

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information to the runtime. Such code is called managed code. All C# and
Visual Basic.NET code is managed by default. VS7 C++ code is not managed
by default, but the compiler can produce managed code by specifying a
command-line switch (/com+).

Managed data: This is data that is allocated and de-allocated by the .NET
runtime's garbage collector. C# and VB.NET data is always managed. VS7
C++ data is unmanaged by default, even when using the /com+ switch, but it
can be marked as managed using the __gc keyword.

Managed classes: This is usually referred to in the context of Managed
Extensions (ME) for C++. When using ME C++, a class can be marked with
the __gc keyword. As the name suggests, this means that the memory for
instances of the class is managed by the garbage collector, but it also means
more than that. The class becomes a fully paid-up member of the .NET
community with the benefits and restrictions that brings. An example of a
benefit is proper interop with classes written in other languages - for example,
a managed C++ class can inherit from a VB class. An example of a restriction
is that a managed class can only inherit from one base class.

2.7 What is reflection?

All .NET compilers produce metadata about the types defined in the modules
they produce. This metadata is packaged along with the module (modules in
turn are packaged together in assemblies), and can be accessed by a
mechanism called reflection. The System.Reflection namespace contains
classes that can be used to interrogate the types for a module/assembly.

Using reflection to access .NET metadata is very similar to using
ITypeLib/ITypeInfo to access type library data in COM, and it is used for
similar purposes - e.g. determining data type sizes for marshaling data across
context/process/machine boundaries.

Reflection can also be used to dynamically invoke methods (see
System.Type.InvokeMember), or even create types dynamically at run-time
(see System.Reflection.Emit.TypeBuilder).

3. Assemblies
3.1 What is an assembly?

An assembly is sometimes described as a logical .EXE or .DLL, and can be an
application (with a main entry point) or a library. An assembly consists of one
or more files (dlls, exes, html files etc), and represents a group of resources,
type definitions, and implementations of those types. An assembly may also
contain references to other assemblies. These resources, types and references
are described in a block of data called a manifest. The manifest is part of the
assembly, thus making the assembly self-describing.

                                Page 62 of 165
An important aspect of assemblies is that they are part of the identity of a
type. The identity of a type is the assembly that houses it combined with the
type name. This means, for example, that if assembly A exports a type called
T, and assembly B exports a type called T, the .NET runtime sees these as two
completely different types. Furthermore, don't get confused between
assemblies and namespaces - namespaces are merely a hierarchical way of
organising type names. To the runtime, type names are type names,
regardless of whether namespaces are used to organise the names. It's the
assembly plus the typename (regardless of whether the type name belongs to
a namespace) that uniquely indentifies a type to the runtime.

Assemblies are also important in .NET with respect to security - many of the
security restrictions are enforced at the assembly boundary.

Finally, assemblies are the unit of versioning in .NET - more on this below.

3.2 How can I produce an assembly?

The simplest way to produce an assembly is directly from a .NET compiler. For
example, the following C# program:

public class CTest
          public CTest()
                   System.Console.WriteLine( "Hello from CTest" );

can be compiled into a library assembly (dll) like this:

csc /t:library ctest.cs

You can then view the contents of the assembly by running the "IL
Disassembler" tool that comes with the .NET SDK.

Alternatively you can compile your source into modules, and then combine
the modules into an assembly using the assembly linker (al.exe). For the C#
compiler, the /target:module switch is used to generate a module instead of
an assembly.

3.3 What is the difference between a private assembly and a
shared assembly?

      Location and visibility: A private assembly is normally used by a
       single application, and is stored in the application's directory, or a sub-
       directory beneath. A shared assembly is normally stored in the global
       assembly cache, which is a repository of assemblies maintained by the
       .NET runtime. Shared assemblies are usually libraries of code which
       many applications will find useful, e.g. the .NET framework classes.

                                     Page 63 of 165
      Versioning: The runtime enforces versioning constraints only on shared
       assemblies, not on private assemblies.

3.4 How do assemblies find each other?

By searching directory paths. There are several factors which can affect the
path (such as the AppDomain host, and application configuration files), but for
private assemblies the search path is normally the application's directory and
its sub-directories. For shared assemblies, the search path is normally same as
the private assembly path plus the shared assembly cache.

3.5 How does assembly versioning work?

Each assembly has a version number called the compatibility version. Also
each reference to an assembly (from another assembly) includes both the
name and version of the referenced assembly.

The version number has four numeric parts (e.g. Assemblies with
either of the first two parts different are normally viewed as incompatible. If
the first two parts are the same, but the third is different, the assemblies are
deemed as 'maybe compatible'. If only the fourth part is different, the
assemblies are deemed compatible. However, this is just the default guideline
- it is the version policy that decides to what extent these rules are enforced.
The version policy can be specified via the application configuration file.

Remember: versioning is only applied to shared assemblies, not private

4. Application Domains
4.1 What is an Application Domain?

An AppDomain can be thought of as a lightweight process. Multiple
AppDomains can exist inside a Win32 process. The primary purpose of the
AppDomain is to isolate an application from other applications.

Win32 processes provide isolation by having distinct memory address spaces.
This is effective, but it is expensive and doesn't scale well. The .NET runtime
enforces AppDomain isolation by keeping control over the use of memory - all
memory in the AppDomain is managed by the .NET runtime, so the runtime
can ensure that AppDomains do not access each other's memory.

4.2 How does an AppDomain get created?

AppDomains are usually created by hosts. Examples of hosts are the Windows
Shell, ASP.NET and IE. When you run a .NET application from the command-
line, the host is the Shell. The Shell creates a new AppDomain for every

                                Page 64 of 165
AppDomains can also be explicitly created by .NET applications. Here is a C#
sample which creates an AppDomain, creates an instance of an object inside it,
and then executes one of the object's methods. Note that you must name the
executable 'appdomaintest.exe' for this code to work as-is.

using System;
using System.Runtime.Remoting;

public class CAppDomainInfo : MarshalByRefObject
          public string GetAppDomainInfo()
                    return "AppDomain = " + AppDomain.CurrentDomain.FriendlyName;


public class App
   public static int Main()
                    AppDomain ad = AppDomain.CreateDomain( "Andy's new domain", null, null
                    ObjectHandle oh = ad.CreateInstance( "appdomaintest", "CAppDomainInfo"
                    CAppDomainInfo adInfo = (CAppDomainInfo)(oh.Unwrap());
                    string info = adInfo.GetAppDomainInfo();

                 Console.WriteLine( "AppDomain info: " + info );
                 return 0;

4.3 Can I write my own .NET host?

Yes. For an example of how to do this, take a look at the source for the
moniker developed by Jason Whittington and Don Box
( ). There is also a code
sample in the .NET SDK called CorHost.

5. Garbage Collection
5.1 What is garbage collection?

Garbage collection is a system whereby a run-time component takes
responsibility for managing the lifetime of objects and the heap memory that
they occupy. This concept is not new to .NET - Java and many other
languages/runtimes have used garbage collection for some time.

5.2 Is it true that objects don't always get destroyed
immediately when the last reference goes away?

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Yes. The garbage collector offers no guarantees about the time when an object
will be destroyed and its memory reclaimed.

There is an interesting thread in the archives, started by Chris Sells, about the
implications of non-deterministic destruction of objects in C#:

In October 2000, Microsoft's Brian Harry posted a lengthy analysis of the

Chris Sells' response to Brian's posting is here:

5.3 Why doesn't the .NET runtime offer deterministic

Because of the garbage collection algorithm. The .NET garbage collector works
by periodically running through a list of all the objects that are currently being
referenced by an application. All the objects that it doesn't find during this
search are ready to be destroyed and the memory reclaimed. The implication
of this algorithm is that the runtime doesn't get notified immediately when the
final reference on an object goes away - it only finds out during the next
sweep of the heap.

Futhermore, this type of algorithm works best by performing the garbage
collection sweep as rarely as possible. Normally heap exhaustion is the trigger
for a collection sweep.

5.4 Is the lack of deterministic destruction in .NET a problem?

It's certainly an issue that affects component design. If you have objects that
maintain expensive or scarce resources (e.g. database locks), you need to
provide some way for the client to tell the object to release the resource when
it is done. Microsoft recommend that you provide a method called Dispose()
for this purpose. However, this causes problems for distributed objects - in a
distributed system who calls the Dispose() method? Some form of reference-
counting or ownership-management mechanism is needed to handle
distributed objects - unfortunately the runtime offers no help with this.

5.5 Does non-deterministic destruction affect the usage of
COM objects from managed code?

Yes. When using a COM object from managed code, you are effectively relying
on the garbage collector to call the final release on your object. If your COM
object holds onto an expensive resource which is only cleaned-up after the

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final release, you may need to provide a new interface on your object which
supports an explicit Dispose() method.

5.6 I've heard that Finalize methods should be avoided. Should
I implement Finalize on my class?

An object with a Finalize method is more work for the garbage collector than
an object without one. Also there are no guarantees about the order in which
objects are Finalized, so there are issues surrounding access to other objects
from the Finalize method. Finally, there is no guarantee that a Finalize method
will get called on an object, so it should never be relied upon to do clean-up of
an object's resources.

Microsoft recommend the following pattern:

public class CTest : IDisposable
          public void Dispose()
                   ... // Cleanup activities

         ~CTest() // C# syntax hiding the Finalize() method

In the normal case the client calls Dispose(), the object's resources are freed,
and the garbage collector is relieved of its Finalizing duties by the call to
SuppressFinalize(). In the worst case, i.e. the client forgets to call Dispose(),
there is a reasonable chance that the object's resources will eventually get
freed by the garbage collector calling Finalize(). Given the limitations of the
garbage collection algorithm this seems like a pretty reasonable approach.

5.7 Do I have any control over the garbage collection

A little. For example, the System.GC class exposes a Collect method - this
forces the garbage collector to collect all unreferenced objects immediately.

5.8 How can I find out what the garbage collector is doing?

Lots of interesting statistics are exported from the .NET runtime via the '.NET
CLR xxx' performance counters. Use Performance Monitor to view them.

6. Serialization
6.1 What is serialization?

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Serialization is the process of converting an object into a stream of bytes.
Deserialization is the opposite process of creating an object from a stream of
bytes. Serialization/Deserialization is mostly used to transport objects (e.g.
during remoting), or to persist objects (e.g. to a file or database).

6.2 Does the .NET Framework have in-built support for

There are two separate mechanisms provided by the .NET class library -
XmlSerializer and SoapFormatter/BinaryFormatter. Microsoft uses
XmlSerializer for Web Services, and uses SoapFormatter/BinaryFormatter for
remoting. Both are available for use in your own code.

6.3 I want to serialize instances of my class. Should I use
XmlSerializer, SoapFormatter or BinaryFormatter?

It depends. XmlSerializer has severe limitations such as the requirement that
the target class has a parameterless constructor, and only public read/write
properties and fields can be serialized. However, on the plus side,
XmlSerializer has good support for customising the XML document that is
produced or consumed. XmlSerializer's features mean that it is most suitable
for cross-platform work, or for constructing objects from existing XML

SoapFormatter and BinaryFormatter have fewer limitations than XmlSerializer.
They can serialize private fields, for example. However they both require that
the target class be marked with the [Serializable] attribute, so like
XmlSerializer the class needs to be written with serialization in mind. Also
there are some quirks to watch out for - for example on deserialization the
constructor of the new object is not invoked.

The choice between SoapFormatter and BinaryFormatter depends on the
application. BinaryFormatter makes sense where both serialization and
deserialization will be performed on the .NET platform and where performance
is important. SoapFormatter generally makes more sense in all other cases,
for ease of debugging if nothing else.

6.4 Can I customise the serialization process?

Yes. XmlSerializer supports a range of attributes that can be used to configure
serialization for a particular class. For example, a field or property can be
marked with the [XmlIgnore] attribute to exclude it from serialization. Another
example is the [XmlElement] attribute, which can be used to specify the XML
element name to be used for a particular property or field.

Serialization via SoapFormatter/BinaryFormatter can also be controlled to
some extent by attributes. For example, the [NonSerialized] attribute is the
equivalent of XmlSerializer's [XmlIgnore] attribute. Ultimate control of the

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serialization process can be acheived by implementing the the ISerializable
interface on the class whose instances are to be serialized.

6.5 Why is XmlSerializer so slow?

There is a once-per-process-per-type overhead with XmlSerializer. So the first
time you serialize or deserialize an object of a given type in an application,
there is a significant delay. This normally doesn't matter, but it may mean, for
example, that XmlSerializer is a poor choice for loading configuration settings
during startup of a GUI application.

6.6 Why do I get errors when I try to serialize a Hashtable?

XmlSerializer will refuse to serialize instances of any class that implements
IDictionary, e.g. Hashtable. SoapFormatter and BinaryFormatter do not have
this restriction.

6.7 XmlSerializer is throwing a generic "There was an error
reflecting MyClass" error. How do I find out what the problem

Look at the InnerException property of the exception that is thrown to get a
more specific error message.

7. Attributes
7.1 What are attributes?

There are at least two types of .NET attribute. The first type I will refer to as a
metadata attribute - it allows some data to be attached to a class or method.
This data becomes part of the metadata for the class, and (like other class
metadata) can be accessed via reflection. An example of a metadata attribute
is [serializable], which can be attached to a class and means that instances of
the class can be serialized.

[serializable] public class CTest {}

The other type of attribute is a context attribute. Context attributes use a
similar syntax to metadata attributes but they are fundamentally different.
Context attributes provide an interception mechanism whereby instance
activation and method calls can be pre- and/or post-processed. If you've come
across Keith Brown's universal delegator you'll be familiar with this idea.

7.2 Can I create my own metadata attributes?

Yes. Simply derive a class from System.Attribute and mark it with the
AttributeUsage attribute. For example:


                                       Page 69 of 165
public class InspiredByAttribute : System.Attribute
          public string InspiredBy;

         public InspiredByAttribute( string inspiredBy )
                  InspiredBy = inspiredBy;

[InspiredBy("Andy Mc's brilliant .NET FAQ")]
class CTest

class CApp
         public static void Main()
                   object[] atts = typeof(CTest).GetCustomAttributes(true);

                  foreach( object att in atts )
                            if( att is InspiredByAttribute )
                                        Console.WriteLine( "Class CTest was inspired by {0}",
((InspiredByAttribute)att).InspiredBy );

7.3 Can I create my own context attributes?

Yes. Take a look at Don Box's sample (called CallThreshold) at, and also Peter Drayton's
Tracehook.NET at

8. Code Access Security
8.1 What is Code Access Security (CAS)?

CAS is the part of the .NET security model that determines whether or not a
piece of code is allowed to run, and what resources it can use when it is
running. For example, it is CAS that will prevent a .NET web applet from
formatting your hard disk.

8.2 How does CAS work?

The CAS security policy revolves around two key concepts - code groups and
permissions. Each .NET assembly is a member of a particular code group,
and each code group is granted the permissions specified in a named
permission set.

For example, using the default security policy, a control downloaded from a
web site belongs to the 'Zone - Internet' code group, which adheres to the
                                       Page 70 of 165
permissions defined by the 'Internet' named permission set. (Naturally the
'Internet' named permission set represents a very restrictive range of

8.3 Who defines the CAS code groups?

Microsoft defines some default ones, but you can modify these and even
create your own. To see the code groups defined on your system, run 'caspol -
lg' from the command-line. On my system it looks like this:

Level = Machine

Code Groups:

1. All code: Nothing
  1.1. Zone - MyComputer: FullTrust
    1.1.1. Honor SkipVerification requests: SkipVerification
  1.2. Zone - Intranet: LocalIntranet
  1.3. Zone - Internet: Internet
  1.4. Zone - Untrusted: Nothing
  1.5. Zone - Trusted: Internet
  1.6. StrongName -
AC1DF1734633C602F8F2D5: Everything

Note the hierarchy of code groups - the top of the hierarchy is the most
general ('All code'), which is then sub-divided into several groups, each of
which in turn can be sub-divided. Also note that (somewhat counter-
intuitively) a sub-group can be associated with a more permissive permission
set than its parent.

8.4 How do I define my own code group?

Use caspol. For example, suppose you trust code from
and you want it have full access to your system, but you want to keep the
default restrictions for all other internet sites. To achieve this, you would add a
new code group as a sub-group of the 'Zone - Internet' group, like this:

caspol -ag 1.3 -site FullTrust

Now if you run caspol -lg you will see that the new group has been added as
group 1.3.1:

   1.3. Zone - Internet: Internet
     1.3.1. Site - FullTrust

                                    Page 71 of 165
Note that the numeric label (1.3.1) is just a caspol invention to make the code
groups easy to manipulate from the command-line. The underlying runtime
never sees it.

8.5 How do I change the permission set for a code group?

Use caspol. If you are the machine administrator, you can operate at the
'machine' level - which means not only that the changes you make become the
default for the machine, but also that users cannot change the permissions to
be more permissive. If you are a normal (non-admin) user you can still modify
the permissions, but only to make them more restrictive. For example, to
allow intranet code to do what it likes you might do this:

caspol -cg 1.2 FullTrust

Note that because this is more permissive than the default policy (on a
standard system), you should only do this at the machine level - doing it at
the user level will have no effect.

8.6 Can I create my own permission set?

Yes. Use caspol -ap, specifying an XML file containing the permissions in the
permission set. To save you some time, here is a sample file corresponding to
the 'Everything' permission set - just edit to suit your needs. When you have
edited the sample, add it to the range of available permission sets like this:

caspol -ap samplepermset.xml

Then, to apply the permission set to a code group, do something like this:

caspol -cg 1.3 SamplePermSet

(By default, 1.3 is the 'Internet' code group)

8.7 I'm having some trouble with CAS. How can I diagnose my

Caspol has a couple of options that might help. First, you can ask caspol to tell
you what code group an assembly belongs to, using caspol -rsg. Similarly, you
can ask what permissions are being applied to a particular assembly using
caspol -rsp.

8.8 I can't be bothered with all this CAS stuff. Can I turn it off?

Yes, as long as you are an administrator. Just run:

caspol -s off

9. Intermediate Language (IL)

                                 Page 72 of 165
9.1 Can I look at the IL for an assembly?

Yes. MS supply a tool called Ildasm which can be used to view the metadata
and IL for an assembly.

9.2 Can source code be reverse-engineered from IL?

Yes, it is often relatively straightforward to regenerate high-level source (e.g.
C#) from IL.

9.3 How can I stop my code being reverse-engineered from

There is currently no simple way to stop code being reverse-engineered from
IL. In future it is likely that IL obfuscation tools will become available, either
from MS or from third parties. These tools work by 'optimising' the IL in such a
way that reverse-engineering becomes much more difficult.

Of course if you are writing web services then reverse-engineering is not a
problem as clients do not have access to your IL.

9.4 Can I write IL programs directly?

Yes. Peter Drayton posted this simple example to the DOTNET mailing list:

.assembly MyAssembly {}
.class MyApp {
  .method static void Main() {
    ldstr   "Hello, IL!"
    call    void System.Console::WriteLine(class System.Object)

Just put this into a file called, and then run ilasm An exe
assembly will be generated.

9.5 Can I do things in IL that I can't do in C#?

Yes. A couple of simple examples are that you can throw exceptions that are
not derived from System.Exception, and you can have non-zero-based arrays.

10. Implications for COM
10.1 Is COM dead?

This subject causes a lot of controversy, as you'll see if you read the mailing
list archives. Take a look at the following two threads:

                                     Page 73 of 165

FWIW my view is as follows: COM is many things, and it's different things to
different people. But to me, COM is fundamentally about how little blobs of
code find other little blobs of code, and how they communicate with each other
when they find each other. COM specifies precisely how this location and
communication takes place. In a 'pure' .NET world, consisting entirely of .NET
objects, little blobs of code still find each other and talk to each other, but they
don't use COM to do so. They use a model which is similar to COM in some
ways - for example, type information is stored in a tabular form packaged with
the component, which is quite similar to packaging a type library with a COM
component. But it's not COM.

So, does this matter? Well, I don't really care about most of the COM stuff
going away - I don't care that finding components doesn't involve a trip to the
registry, or that I don't use IDL to define my interfaces. But there is one thing
that I wouldn't like to go away - I wouldn't like to lose the idea of interface-
based development. COM's greatest strength, in my opinion, is its insistence
on a cast-iron separation between interface and implementation.
Unfortunately, the .NET framework seems to make no such insistence - it lets
you do interface-based development, but it doesn't insist. Some people would
argue that having a choice can never be a bad thing, and maybe they're right,
but I can't help feeling that maybe it's a backward step.

10.2 Is DCOM dead?

Pretty much, for .NET developers. The .NET Framework has a new remoting
model which is not based on DCOM. Of course DCOM will still be used in
interop scenarios.

10.3 Is MTS/COM+ dead?

No. The approach for the first .NET release is to provide access to the existing
COM+ services (through an interop layer) rather than replace the services with
native .NET ones. Various tools and attributes are provided to try to make this
as painless as possible. The PDC release of the .NET SDK includes interop
support for core services (JIT activation, transactions) but not some of the
higher level services (e.g. COM+ Events, Queued components).

Over time it is expected that interop will become more seamless - this may
mean that some services become a core part of the CLR, and/or it may mean
that some services will be rewritten as managed code which runs on top of the

For more on this topic, search for postings by Joe Long in the archives - Joe is
the MS group manager for COM+. Start with this message:

                                 Page 74 of 165

10.4 Can I use COM components from .NET programs?

Yes. COM components are accessed from the .NET runtime via a Runtime
Callable Wrapper (RCW). This wrapper turns the COM interfaces exposed by
the COM component into .NET-compatible interfaces. For oleautomation
interfaces, the RCW can be generated automatically from a type library. For
non-oleautomation interfaces, it may be necessary to develop a custom RCW
which manually maps the types exposed by the COM interface to .NET-
compatible types.

Here's a simple example for those familiar with ATL. First, create an ATL
component which implements the following IDL:

import "oaidl.idl";
import "ocidl.idl";

         helpstring("ICppName Interface"),

interface ICppName : IUnknown
          [helpstring("method SetName")] HRESULT SetName([in] BSTR name);
          [helpstring("method GetName")] HRESULT GetName([out,retval] BSTR *pName );

         helpstring("cppcomserver 1.0 Type Library")
                   helpstring("CppName Class")
          coclass CppName
                   [default] interface ICppName;

When you've built the component, you should get a typelibrary. Run the
TLBIMP utility on the typelibary, like this:

                                   Page 75 of 165
tlbimp cppcomserver.tlb

If successful, you will get a message like this:

Typelib imported successfully to CPPCOMSERVERLib.dll

You now need a .NET client - let's use C#. Create a .cs file containing the
following code:

using System;

public class MainApp
          static public void Main()
                   CppName cppname = new CppName();
                   cppname.SetName( "bob" );
                   Console.WriteLine( "Name is " + cppname.GetName() );

Note that we are using the type library name as a namespace, and the COM
class name as the class. Alternatively we could have used
CPPCOMSERVERLib.CppName for the class name and gone without the using
CPPCOMSERVERLib statement.

Compile the C# code like this:

csc /r:cppcomserverlib.dll csharpcomclient.cs

Note that the compiler is being told to reference the DLL we previously
generated from the typelibrary using TLBIMP.

You should now be able to run csharpcomclient.exe, and get the following
output on the console:

Name is bob

10.5 Can I use .NET components from COM programs?

Yes. .NET components are accessed from COM via a COM Callable Wrapper
(CCW). This is similar to a RCW (see previous question), but works in the
opposite direction. Again, if the wrapper cannot be automatically generated by
the .NET development tools, or if the automatic behaviour is not desirable, a
custom CCW can be developed. Also, for COM to 'see' the .NET component,
the .NET component must be registered in the registry.

Here's a simple example. Create a C# file called testcomserver.cs and put the
following in it:

using System;

                                      Page 76 of 165
using System.Runtime.InteropServices;

namespace AndyMc
       public class CSharpCOMServer
                 public CSharpCOMServer() {}
                 public void SetName( string name ) { m_name = name; }
                 public string GetName() { return m_name; }
                 private string m_name;

Then compile the .cs file as follows:

csc /target:library testcomserver.cs

You should get a dll, which you register like this:

regasm testcomserver.dll /tlb:testcomserver.tlb /codebase

Now you need to create a client to test your .NET COM component. VBScript
will do - put the following in a file called comclient.vbs:

Dim dotNetObj
Set dotNetObj = CreateObject("AndyMc.CSharpCOMServer")
dotNetObj.SetName ("bob")
MsgBox "Name is " & dotNetObj.GetName()

and run the script like this:

wscript comclient.vbs

And hey presto you should get a message box displayed with the text "Name
is bob".

An alternative to the approach above it to use the moniker developed
by Jason Whittington and Don Box. Go to to check it out.

10.6 Is ATL redundant in the .NET world?

Yes, if you are writing applications that live inside the .NET framework. Of
course many developers may wish to continue using ATL to write C++ COM
components that live outside the framework, but if you are inside you will
almost certainly want to use C#. Raw C++ (and therefore ATL which is based
on it) doesn't have much of a place in the .NET world - it's just too near the
metal and provides too much flexibility for the runtime to be able to manage

11. Miscellaneous

                                       Page 77 of 165
11.1 How does .NET remoting work?

.NET remoting involves sending messages along channels. Two of the standard
channels are HTTP and TCP. TCP is intended for LANs only - HTTP can be used
for LANs or WANs (internet).

Support is provided for multiple message serializarion formats. Examples are
SOAP (XML-based) and binary. By default, the HTTP channel uses SOAP (via
the .NET runtime Serialization SOAP Formatter), and the TCP channel uses
binary (via the .NET runtime Serialization Binary Formatter). But either
channel can use either serialization format.

There are a number of styles of remote access:

      SingleCall. Each incoming request from a client is serviced by a new
       object. The object is thrown away when the request has finished.

      Singleton. All incoming requests from clients are processed by a single
       server object.

      Client-activated object. This is the old stateful (D)COM model whereby
       the client receives a reference to the remote object and holds that
       reference (thus keeping the remote object alive) until it is finished with

Distributed garbage collection of objects is managed by a system called 'leased
based lifetime'. Each object has a lease time, and when that time expires the
object is disconnected from the .NET runtime remoting infrastructure. Objects
have a default renew time - the lease is renewed when a successful call is
made from the client to the object. The client can also explicitly renew the

If you're interested in using XML-RPC as an alternative to SOAP, take a look at
Charles Cook's XML-RPC.Net site at

11.2 How can I get at the Win32 API from a .NET program?

Use P/Invoke. This uses similar technology to COM Interop, but is used to
access static DLL entry points instead of COM objects. Here is an example of
C# calling the Win32 MessageBox function:

using System;
using System.Runtime.InteropServices;

class MainApp
         [DllImport("user32.dll", EntryPoint="MessageBox", SetLastError=true,
         public static extern int MessageBox(int hWnd, String strMessage, String strCaption,
uint uiType);

                                      Page 78 of 165
         public static void Main()
                   MessageBox( 0, "Hello, this is PInvoke in operation!", ".NET", 0 );

12. Class Library
12.1 File I/O

12.1.1 How do I read from a text file?

First, use a System.IO.FileStream object to open the file:

FileStream fs = new FileStream( @"c:\test.txt", FileMode.Open, FileAccess.Read );

FileStream inherits from Stream, so you can wrap the FileStream object with a
StreamReader object. This provides a nice interface for processing the stream
line by line:

StreamReader sr = new StreamReader( fs );
string curLine;
while( (curLine = sr.ReadLine()) != null )
         Console.WriteLine( curLine );

Finally close the StreamReader object:


Note that this will automatically call Close() on the underlying Stream object,
so an explicit fs.Close() is not required.

12.1.2 How do I write to a text file?

Similar to the read example, except use StreamWriter instead of

12.1.3 How do I read/write binary files?

Similar to text files, except wrap the FileStream object with a
BinaryReader/Writer object instead of a StreamReader/Writer object.

12.2 Text Processing

12.2.1 Are regular expressions supported?

Yes. Use the System.Text.RegularExpressions.Regex class. For example, the
following code updates the title in an HTML file:

FileStream fs = new FileStream( "test.htm", FileMode.Open, FileAccess.Read );
StreamReader sr = new StreamReader( fs );

                                       Page 79 of 165
Regex r = new Regex( "<TITLE>(.*)</TITLE>" );
string s;
while( (s = sr.ReadLine()) != null )
          if( r.IsMatch( s ) )
                    s = r.Replace( s, "<TITLE>New and improved ${1}</TITLE>" );
          Console.WriteLine( s );

12.3 Internet

12.3.1 How do I download a web page?

First use the System.Net.WebRequestFactory class to acquire a WebRequest

WebRequest request = WebRequest.Create( "http://localhost" );

Then ask for the response from the request:

WebResponse response = request.GetResponse();

The GetResponse method blocks until the download is complete. Then you can
access the response stream like this:

Stream s = response.GetResponseStream();

// Output the downloaded stream to the console
StreamReader sr = new StreamReader( s );
string line;
while( (line = sr.ReadLine()) != null )
          Console.WriteLine( line );

Note that WebRequest and WebReponse objects can be downcast to
HttpWebRequest and HttpWebReponse objects respectively, to access http-
specific functionality.

12.3.2 How do I use a proxy?

Two approaches - to affect all web requests do this:

System.Net.GlobalProxySelection.Select = new WebProxy( "proxyname", 80 );

Alternatively, to set the proxy for a specific web request, do this:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create( "http://localhost" );
request.Proxy = new WebProxy( "proxyname", 80 );

12.4 XML

12.4.1 Is DOM supported?

                                    Page 80 of 165
Yes. Take this example XML document:


This document can be parsed as follows:

XmlDocument doc = new XmlDocument();
doc.Load( "test.xml" );

XmlNode root = doc.DocumentElement;

foreach( XmlNode personElement in root.ChildNodes )
         Console.WriteLine( personElement.FirstChild.Value.ToString() );

The output is:


12.4.2 Is SAX supported?

No. Instead, a new XmlReader/XmlWriter API is offered. Like SAX it is stream-
based but it uses a 'pull' model rather than SAX's 'push' model. Here's an

XmlTextReader reader = new XmlTextReader( "test.xml" );

while( reader.Read() )
         if( reader.NodeType == XmlNodeType.Element && reader.Name == "PERSON" )
                   reader.Read(); // Skip to the child text
                   Console.WriteLine( reader.Value );

12.4.3 Is XPath supported?

Yes, via the XPathXXX classes:

XPathDocument xpdoc = new XPathDocument("test.xml");
XPathNavigator nav = xpdoc.CreateNavigator();
XPathExpression expr = nav.Compile("descendant::PEOPLE/PERSON");

XPathNodeIterator iterator = nav.Select(expr);
while (iterator.MoveNext())

12.5 Threading

12.5.1 Is multi-threading supported?

                                     Page 81 of 165
Yes, there is extensive support for multi-threading. New threads can be
spawned, and there is a system-provided threadpool which applications can

12.5.2 How do I spawn a thread?

Create an instance of a System.Threading.Thread object, passing it an
instance of a ThreadStart delegate that will be executed on the new thread.
For example:

class MyThread
         public MyThread( string initData )
                  m_data = initData;
                  m_thread = new Thread( new ThreadStart(ThreadMain) );

        // ThreadMain() is executed on the new thread.
        private void ThreadMain()
                 Console.WriteLine( m_data );

        public void WaitUntilFinished()

        private Thread m_thread;
        private string m_data;

In this case creating an instance of the MyThread class is sufficient to spawn
the thread and execute the MyThread.ThreadMain() method:

MyThread t = new MyThread( "Hello, world." );

12.5.3 How do I stop a thread?

There are several options. First, you can use your own communication
mechanism to tell the ThreadStart method to finish. Alternatively the Thread
class has in-built support for instructing the thread to stop. The two principle
methods are Thread.Interrupt() and Thread.Abort(). The former will cause a
ThreadInterruptedException to be thrown on the thread when it next goes into
a WaitJoinSleep state. In other words, Thread.Interrupt is a polite way of
asking the thread to stop when it is no longer doing any useful work. In
contrast, Thread.Abort() throws a ThreadAbortException regardless of what
the thread is doing. Furthermore, the ThreadAbortException cannot normally
be caught (though the ThreadStart's finally method will be executed).
Thread.Abort() is a heavy-handed mechanism which should not normally be

                                     Page 82 of 165
12.5.4 How do I use the thread pool?

By passing an instance of a WaitCallback delegate to the
ThreadPool.QueueUserWorkItem() method:

class CApp
         static void Main()
                   string s = "Hello, World";
                   ThreadPool.QueueUserWorkItem( new WaitCallback( DoWork ), s );

                   Thread.Sleep( 1000 );       // Give time for work item to be executed

          // DoWork is executed on a thread from the thread pool.
          static void DoWork( object state )
                    Console.WriteLine( state );

12.5.5 How do I know when my thread pool work item has completed?

There is no way to query the thread pool for this information. You must put
code into the WaitCallback method to signal that it has completed. Events are
useful for this.

12.5.6 How do I prevent concurrent access to my data?

Each object has a concurrency lock (critical section) associated with it. The
System.Threading.Monitor.Enter/Exit methods are used to acquire and release
this lock. For example, instances of the following class only allow one thread at
a time to enter method f():

class C
          public void f()

C# has a 'lock' keyword which provides a convenient shorthand for the code

class C

                                        Page 83 of 165
          public void f()

Note that calling Monitor.Enter(myObject) does NOT mean that all access to
myObject is serialized. It means that the synchronisation lock associated with
myObject has been acquired, and no other thread can acquire that lock until
Monitor.Exit(o) is called. In other words, this class is functionally equivalent to
the classes above:

class C
          public void f()
                   lock( m_object )

          private m_object = new object();

12.6 Tracing

12.6.1 Is there built-in support for tracing/logging?

Yes, in the System.Diagnostics namespace. There are two main classes that
deal with tracing - Debug and Trace. They both work in a similar way - the
difference is that tracing from the Debug class only works in builds that have
the DEBUG symbol defined, whereas tracing from the Trace class only works in
builds that have the TRACE symbol defined. Typically this means that you
should use System.Diagnostics.Trace.WriteLine for tracing that you want to
work in debug and release builds, and System.Diagnostics.Debug.WriteLine for
tracing that you want to work only in debug builds.

12.6.2 Can I redirect tracing to a file?

Yes. The Debug and Trace classes both have a Listeners property, which is a
collection of sinks that receive the tracing that you send via Debug.WriteLine
and Trace.WriteLine respectively. By default the Listeners collection contains a
single sink, which is an instance of the DefaultTraceListener class. This sends
output to the Win32 OutputDebugString() function and also the
System.Diagnostics.Debugger.Log() method. This is useful when debugging,
but if you're trying to trace a problem at a customer site, redirecting the
output to a file is more appropriate. Fortunately, the TextWriterTraceListener
class is provided for this purpose.

                                      Page 84 of 165
Here's how to use the TextWriterTraceListener class to redirect Trace output to
a file:

FileStream fs = new FileStream( @"c:\log.txt", FileMode.Create, FileAccess.Write );
Trace.Listeners.Add( new TextWriterTraceListener( fs ) );

Trace.WriteLine( @"This will be writen to c:\log.txt!" );

Note the use of Trace.Listeners.Clear() to remove the default listener. If you
don't do this, the output will go to the file and OutputDebugString(). Typically
this is not what you want, because OutputDebugString() imposes a big
performance hit.

12.6.3 Can I customise the trace output?

Yes. You can write your own TraceListener-derived class, and direct all output
through it. Here's a simple example, which derives from
TextWriterTraceListener (and therefore has in-built support for writing to files,
as shown above) and adds timing information and the thread ID for each trace

class MyListener : TextWriterTraceListener
         public MyListener( Stream s ) : base(s)

         public override void WriteLine( string s )
                  Writer.WriteLine( "{0:D8} [{1:D4}] {2}",
                            Environment.TickCount - m_startTickCount,
                            s );

         protected int m_startTickCount = Environment.TickCount;

(Note that this implementation is not complete - the TraceListener.Write
method is not overridden for example.)

The beauty of this approach is that when an instance of MyListener is added to
the Trace.Listeners collection, all calls to Trace.WriteLine() go through
MyListener, including calls made by referenced assemblies that know nothing
about the MyListener class.

13. Resources
13.1 Recommended books

                                       Page 85 of 165
I recommend the following books, either because I personally like them, or
because I think they are well regarded by other .NET developers. (Note that I
get a commission from Amazon if you buy a book after following one of these

     Applied Microsoft .NET Framework Programming - Jeffrey Richter
      Much anticipated, mainly due to Richter's superb Win32 books, and most
      people think it delivers. The 'applied' is a little misleading - this book is
      mostly about how the .NET Framework works 'under the hood'.
      Examples are in C#, but there is also a separate VB edition of the book.

     Essential .NET Volume 1, The Common Language Runtime - Don Box
      A superb book, which I recommend to anyone who already has some
      .NET development experience, and wants to get a deeper understanding
      of CLR fundamentals. It's clear that Box has deeply researched the
      topics and then carefully constructed a coherent story around his
      findings. It's rare to find such craft in a.NET text.

     C# and the .NET Platform, 2nd Edition - Andrew Troelsen
      Regarded by many as the best all round C#/.NET book. Wide coverage
      including Windows Forms, COM interop, ADO.NET, ASP.NET etc. Troelsen
      also has a respected VB.NET book called Visual Basic .NET and the .NET
      Platform: An Advanced Guide.

     Programming Windows with C# - Charles Petzold
      Another slightly misleading title - this book is solely about GUI
      programming - Windows Forms and GDI+. Well written, with
      comprehensive coverage. My only (minor) criticism is that the book
      sticks closely to the facts, without offering a great deal in the way of
      'tips and tricks' for real-world apps.

     Windows Forms Programming in C# - Chris Sells
      I haven't read this myself yet, but anything Sells writes is usually worth

     Developing Applications with Visual Studio.NET - Richard Grimes
      Covers lots of interesting topics that other books don't, including ATL7,
      Managed C++, internationalization, remoting, as well as the more run-
      of-the-mill CLR and C# stuff. Also a lot of info on the Visual Studio IDE.
      This book is most suitable for reasonably experienced C++

     Programming Microsoft Visual Basic .NET - Francesco Balena
      Balena is a reknowned VB-er, and the reviews of his VB.NET book are

     .NET and COM - The Complete Interoperability Guide - Adam Nathan
      Don't be put off by the size - this book is very easy to digest thanks to

                                 Page 86 of 165
       the superb writing style. The bible of .NET/COM interop.

      Advanced .NET Remoting - Ingo Rammer
       Widely recommended.

13.2 Internet Resources

      The Microsoft .NET homepage is at
       Microsoft also host GOTDOTNET.
      DevX host the .NET Zone.
    is a superb set of links to
       .NET resources.
      Chris Sells has a great set of .NET links at
      microsoft.public.dotnet.* newsgroups
      My C# FAQ for C++ Programmers.

13.3 Weblogs

The following Weblogs ('blogs') have regular .NET content:

      The .NET Guy (Brad Wilson)
      Charles Cook: Developer of XML-RPC.NET.
      Gwyn Cole: Co-author of Developing WMI solutions.
      Chris Brumme
      Brad Abrams
      Don Box
      John Lam
      Peter Drayton: Co-author of C# Essentials and C# in a Nutshell.
      Ingo Rammer: Author of Advanced .NET remoting.
      Drew Marsh
      Tomas Restrepo
      Justin Rudd
      Simon Fell: Developer of PocketSOAP.
      Richard Caetano
      Chris Sells

13.4 Sample code & utilities

Lutz Roeder has some great utilities and libraries at

Peter Drayton's .NET Goodies page is at

Don Box & Jason Whittington's COM moniker at

                                Page 87 of 165
Mike Woodring has some .NET samples at

Charles Cook's XML-RPC.Net library is available at

  Microsoft SQL Server # Interview Questions - (last updated on             )

     Transact-SQL Optimization Tips
     Index Optimization tips
     T-SQL Queries
     Data Types
     Index
     Joins
     Lock
     Stored Procedure
     Trigger
     View
     Transaction
     Other
     XML
     Tools
     Permission
     Administration

Transact-SQL Optimization Tips

     Use views and stored procedures instead of heavy-duty queries.
      This can reduce network traffic, because your client will send to server
      only stored procedure or view name (perhaps with some parameters)
      instead of large heavy-duty queries text. This can be used to facilitate
      permission management also, because you can restrict user access to
      table columns they should not see.
     Try to use constraints instead of triggers, whenever possible.
      Constraints are much more efficient than triggers and can boost
      performance. So, you should use constraints instead of triggers,
      whenever possible.
     Use table variables instead of temporary tables.
      Table variables require less locking and logging resources than
      temporary tables, so table variables should be used whenever possible.
      The table variables are available in SQL Server 2000 only.
     Try to use UNION ALL statement instead of UNION, whenever
      The UNION ALL statement is much faster than UNION, because UNION
      ALL statement does not look for duplicate rows, and UNION statement
      does look for duplicate rows, whether or not they exist.
     Try to avoid using the DISTINCT clause, whenever possible.
      Because using the DISTINCT clause will result in some performance
      degradation, you should use this clause only when it is necessary.

                                Page 88 of 165
     Try to avoid using SQL Server cursors, whenever possible.
      SQL Server cursors can result in some performance degradation in
      comparison with select statements. Try to use correlated sub-query or
      derived tables, if you need to perform row-by-row operations.
     Try to avoid the HAVING clause, whenever possible.
      The HAVING clause is used to restrict the result set returned by the
      GROUP BY clause. When you use GROUP BY with the HAVING clause, the
      GROUP BY clause divides the rows into sets of grouped rows and
      aggregates their values, and then the HAVING clause eliminates
      undesired aggregated groups. In many cases, you can write your select
      statement so, that it will contain only WHERE and GROUP BY clauses
      without HAVING clause. This can improve the performance of your
     If you need to return the total table's row count, you can use
      alternative way instead of SELECT COUNT(*) statement.
      Because SELECT COUNT(*) statement make a full table scan to return
      the total table's row count, it can take very many time for the large
      table. There is another way to determine the total row count in a table.
      You can use sysindexes system table, in this case. There is ROWS
      column in the sysindexes table. This column contains the total row count
      for each table in your database. So, you can use the following select
      statement instead of SELECT COUNT(*): SELECT rows FROM sysindexes
      WHERE id = OBJECT_ID('table_name') AND indid < 2 So, you can
      improve the speed of such queries in several times.
     Include SET NOCOUNT ON statement into your stored procedures
      to stop the message indicating the number of rows affected by a
      T-SQL statement.
      This can reduce network traffic, because your client will not receive the
      message indicating the number of rows affected by a T-SQL statement.
     Try to restrict the queries result set by using the WHERE clause.
      This can results in good performance benefits, because SQL Server will
      return to client only particular rows, not all rows from the table(s). This
      can reduce network traffic and boost the overall performance of the
     Use the select statements with TOP keyword or the SET
      ROWCOUNT statement, if you need to return only the first n
      This can improve performance of your queries, because the smaller
      result set will be returned. This can also reduce the traffic between the
      server and the clients.
     Try to restrict the queries result set by returning only the
      particular columns from the table, not all table's columns.
      This can results in good performance benefits, because SQL Server will
      return to client only particular columns, not all table's columns. This can
      reduce network traffic and boost the overall performance of the query.

2.avoid more number of triggers on the table
3.unnecessary complicated joins

                                Page 89 of 165
4.correct use of Group by clause with the select list worst cases Denormalization

Index Optimization tips

      Every index increases the time in takes to perform INSERTS, UPDATES
       and DELETES, so the number of indexes should not be very much. Try to
       use maximum 4-5 indexes on one table, not more. If you have read-only
       table, then the number of indexes may be increased.
      Keep your indexes as narrow as possible. This reduces the size of the
       index and reduces the number of reads required to read the index.
      Try to create indexes on columns that have integer values rather than
       character values.
      If you create a composite (multi-column) index, the order of the columns
       in the key are very important. Try to order the columns in the key as to
       enhance selectivity, with the most selective columns to the leftmost of
       the key.
      If you want to join several tables, try to create surrogate integer keys
       for this purpose and create indexes on their columns.
      Create surrogate integer primary key (identity for example) if your table
       will not have many insert operations.
      Clustered indexes are more preferable than nonclustered, if you need to
       select by a range of values or you need to sort results set with GROUP
       BY or ORDER BY.
      If your application will be performing the same query over and over on
       the same table, consider creating a covering index on the table.
      You can use the SQL Server Profiler Create Trace Wizard with "Identify
       Scans of Large Tables" trace to determine which tables in your database
       may need indexes. This trace will show which tables are being scanned
       by queries instead of using an index.
      You can use sp_MSforeachtable undocumented stored procedure to
       rebuild all indexes in your database. Try to schedule it to execute during
       CPU idle time and slow production periods.
       sp_MSforeachtable @command1="print '?' DBCC DBREINDEX ('?')"

                               T-SQL Queries

   1. 2 tables

       Employee Phone
       empname empid
       salary  phnumber

   2. Select all employees who doesn't have phone?
      SELECT empname
      FROM Employee
      WHERE (empid NOT IN

                                 Page 90 of 165
     FROM phone))
3.   Select the employee names who is having more than one phone
     SELECT empname
     FROM employee
     WHERE (empid IN
     (SELECT empid
     FROM phone
     GROUP BY empid
     HAVING COUNT(empid) > 1))
4.   Select the details of 3 max salaried employees from employee table.
     SELECT TOP 3 empid, salary
     FROM employee
     ORDER BY salary DESC
5.   Display all managers from the table. (manager id is same as emp id)
     SELECT empname
     FROM employee
     WHERE (empid IN
     FROM employee))
6.   Write a Select statement to list the Employee Name, Manager Name
     under a particular manager?
     SELECT e1.empname AS EmpName, e2.empname AS ManagerName
     FROM Employee e1 INNER JOIN
     Employee e2 ON e1.mgrid = e2.empid
     ORDER BY e2.mgrid
7.   2 tables emp and phone.
     emp fields are - empid, name
     Ph fields are - empid, ph (office, mobile, home). Select all employees
     who doesn't have any ph nos.
     SELECT *
     FROM employee LEFT OUTER JOIN
     phone ON employee.empid = phone.empid
     WHERE ( IS NULL OR = ' ')
     AND ( IS NULL OR = ' ')
     AND (phone.home IS NULL OR phone.home = ' ')
8.   Find employee who is living in more than one city.
     Two Tables:

     Emp         City

9. SELECT empname, fname, lname
   FROM employee
   WHERE (empid IN
   (SELECT empid
   FROM city

                               Page 91 of 165
   GROUP BY empid
   HAVING COUNT(empid) > 1))
10.       Find all employees who is living in the same city. (table is same as
   SELECT fname
   FROM employee
   WHERE (empid IN
   (SELECT empid
   FROM city a
   WHERE city IN
   (SELECT city
   FROM city b
   GROUP BY city
   HAVING COUNT(city) > 1)))
11.       There is a table named MovieTable with three columns -
   moviename, person and role. Write a query which gets the movie details
   where Mr. Amitabh and Mr. Vinod acted and their role is actor.
   SELECT DISTINCT m1.moviename
   FROM MovieTable m1 INNER JOIN
   MovieTable m2 ON m1.moviename = m2.moviename
   WHERE (m1.person = 'amitabh' AND m2.person = 'vinod' OR
   m2.person = 'amitabh' AND m1.person = 'vinod') AND (m1.role =
   'actor') AND (m2.role = 'actor')
   ORDER BY m1.moviename
12.       There are two employee tables named emp1 and emp2. Both
   contains same structure (salary details). But Emp2 salary details are
   incorrect and emp1 salary details are correct. So, write a query which
   corrects salary details of the table emp2
   update a set a.sal=b.sal from emp1 a, emp2 b where a.empid=b.empid
13.       Given a Table named ―Students‖ which contains studentid,
   subjectid and marks. Where there are 10 subjects and 50 students.
   Write a Query to find out the Maximum marks obtained in each subject.
14.       In this same tables now write a SQL Query to get the studentid
   also to combine with previous results.
15.       Three tables – student , course, marks – how do go at finding
   name of the students who got max marks in the diff courses.
   SELECT, AS coursename, marks.sid,
   student ON marks.sid = student.sid INNER JOIN
   course ON marks.cid = course.cid
   WHERE (marks.mark =
   (SELECT MAX(Mark)
   FROM Marks MaxMark
   WHERE MaxMark.cID = Marks.cID))
16.       There is a table day_temp which has three columns dayid, day and
   temperature. How do I write a query to get the difference of
   temperature among each other for seven days of a week?
   SELECT a.dayid, a.dday, a.tempe, a.tempe - b.tempe AS Difference

                             Page 92 of 165
   FROM day_temp a INNER JOIN
   day_temp b ON a.dayid = b.dayid + 1
   Select, from temperature a, temperature b
17.      There is a table which contains the names like this. a1, a2, a3, a3,
   a4, a1, a1, a2 and their salaries. Write a query to get grand total salary,
   and total salaries of individual employees in one query.
   SELECT empid, SUM(salary) AS salary
   FROM employee
   ORDER BY empid
18.      How to know how many tables contains empno as a column
   in a database?
   SELECT COUNT(*) AS Counter
   FROM syscolumns
   WHERE (name = 'empno')
19.      Find duplicate rows in a table? OR I have a table with one
   column which has many records which are not distinct. I need to
   find the distinct values from that column and number of times it‟s
   SELECT sid, mark, COUNT(*) AS Counter
   FROM marks
   GROUP BY sid, mark
   HAVING (COUNT(*) > 1)
20.      How to delete the rows which are duplicate (don‟t delete
   both duplicate records).
   DELETE yourtable
   FROM yourtable a
   WHERE (SELECT COUNT(*) FROM yourtable b WHERE b.name1 =
   a.name1 AND b.age1 = a.age1) > 1
   WHILE @@rowcount > 0
     DELETE yourtable
     FROM yourtable a
     WHERE (SELECT COUNT(*) FROM yourtable b WHERE b.name1 =
   a.name1 AND b.age1 = a.age1) > 1
21.      How to find 6th highest salary
   SELECT TOP 1 salary
   FROM employee
   ORDER BY salary DESC) a
   ORDER BY salary
22.      Find top salary among two tables
   SELECT TOP 1 sal
   FROM (SELECT MAX(sal) AS sal
   FROM sal1

                             Page 93 of 165
   SELECT MAX(sal) AS sal
   FROM sal2) a
23.     Write a query to convert all the letters in a word to upper
   SELECT UPPER('test')
24.     Write a query to round up the values of a number. For
   example even if the user enters 7.1 it should be rounded up to 8.
25.     Write a SQL Query to find first day of month?
   GETDATE())) AS FirstDay

        Datepart    Abbreviations
  year             yy, yyyy
  quarter          qq, q
  month            mm, m
  dayofyear        dy, y
  day              dd, d
  week             wk, ww
  weekday          dw
  hour             hh
  minute           mi, n
  second           ss, s
  millisecond      ms

26.      Table A contains column1 which is primary key and has 2 values
   (1, 2) and Table B contains column1 which is primary key and has 2
   values (2, 3). Write a query which returns the values that are not
   common for the tables and the query should return one column with 2
   SELECT tbla.a
   FROM tbla, tblb
   WHERE tbla.a <>
   (SELECT tblb.a
   FROM tbla, tblb
   WHERE tbla.a = tblb.a)
   SELECT tblb.a
   FROM tbla, tblb
   WHERE tblb.a <>
   (SELECT tbla.a
   FROM tbla, tblb
   WHERE tbla.a = tblb.a)

  OR (better approach)


                              Page 94 of 165
   FROM tbla
   (SELECT a
   FROM tblb)
   FROM tblb
   (SELECT a
   FROM tbla)
27.       There are 3 tables Titles, Authors and Title-Authors (check PUBS
   db). Write the query to get the author name and the number of books
   written by that author, the result should start from the author who has
   written the maximum number of books and end with the author who has
   written the minimum number of books.
   SELECT authors.au_lname, COUNT(*) AS BooksCount
   FROM authors INNER JOIN
   titleauthor ON authors.au_id = titleauthor.au_id INNER JOIN
   titles ON titles.title_id = titleauthor.title_id
   GROUP BY authors.au_lname
   ORDER BY BooksCount DESC
   UPDATE emp_master
   SET emp_sal =
   WHEN emp_sal > 0 AND emp_sal <= 20000 THEN (emp_sal * 1.01)
   WHEN emp_sal > 20000 THEN (emp_sal * 1.02)
29.       List all products with total quantity ordered, if quantity ordered is
   null show it as 0.
   > 0 THEN SUM(qty) END AS tot
   product ON [order].prodid = product.prodid
   GROUP BY name
   coke 60
   mirinda 0
   pepsi 10
30.       ANY, SOME, or ALL?
   ALL means greater than every value--in other words, greater than the
   maximum value. For example, >ALL (1, 2, 3) means greater than 3.
   ANY means greater than at least one value, that is, greater than the
   minimum. So >ANY (1, 2, 3) means greater than 1. SOME is an SQL-92
   standard equivalent for ANY.
31.       IN & = (difference in correlated sub query)


                              Page 95 of 165
32.      What is Index? It‟s purpose?
   Indexes in databases are similar to indexes in books. In a database, an
   index allows the database program to find data in a table without
   scanning the entire table. An index in a database is a list of values in a
   table with the storage locations of rows in the table that contain each
   value. Indexes can be created on either a single column or a
   combination of columns in a table and are implemented in the form of B-
   trees. An index contains an entry with one or more columns (the search
   key) from each row in a table. A B-tree is sorted on the search key, and
   can be searched efficiently on any leading subset of the search key. For
   example, an index on columns A, B, C can be searched efficiently on A,
   on A, B, and A, B, C.
33.      Explain about Clustered and non clustered index? How to
   choose between a Clustered Index and a Non-Clustered Index?
   There are clustered and nonclustered indexes. A clustered index is a
   special type of index that reorders the way records in the table are
   physically stored. Therefore table can have only one clustered index. The
   leaf nodes of a clustered index contain the data pages.
   A nonclustered index is a special type of index in which the logical order
   of the index does not match the physical stored order of the rows on
   disk. The leaf nodes of a nonclustered index does not consist of the data
   pages. Instead, the leaf nodes contain index rows.
   Consider using a clustered index for:
      o Columns that contain a large number of distinct values.
      o Queries that return a range of values using operators such as
         BETWEEN, >, >=, <, and <=.
      o Columns that are accessed sequentially.
      o Queries that return large result sets.
         Non-clustered indexes have the same B-tree structure as clustered
         indexes, with two significant differences:
      o The data rows are not sorted and stored in order based on their
         non-clustered keys.
      o The leaf layer of a non-clustered index does not consist of the data
         pages. Instead, the leaf nodes contain index rows. Each index row
         contains the non-clustered key value and one or more row locators
         that point to the data row (or rows if the index is not unique)
         having the key value.
      o Per table only 249 non clustered indexes.
34.      Disadvantage of index?
   Every index increases the time in takes to perform INSERTS, UPDATES
   and DELETES, so the number of indexes should not be very much.
35.      Given a scenario that I have a 10 Clustered Index in a Table
   to all their 10 Columns. What are the advantages and
   A: Only 1 clustered index is possible.
36.      How can I enforce to use particular index?
   You can use index hint (index=<index_name>) after the table name.
   SELECT au_lname FROM authors (index=aunmind)

                             Page 96 of 165
37.       What is Index Tuning?
   One of the hardest tasks facing database administrators is the selection
   of appropriate columns for non-clustered indexes. You should consider
   creating non-clustered indexes on any columns that are frequently
   referenced in the WHERE clauses of SQL statements. Other good
   candidates are columns referenced by JOIN and GROUP BY operations.
   You may wish to also consider creating non-clustered indexes that cover
   all of the columns used by certain frequently issued queries. These
   queries are referred to as ―covered queries‖ and experience excellent
   performance gains.
   Index Tuning is the process of finding appropriate column for non-
   clustered indexes.
   SQL Server provides a wonderful facility known as the Index Tuning
   Wizard which greatly enhances the index selection process.
38.       Difference between Index defrag and Index rebuild?
   When you create an index in the database, the index information used
   by queries is stored in index pages. The sequential index pages are
   chained together by pointers from one page to the next. When changes
   are made to the data that affect the index, the information in the index
   can become scattered in the database. Rebuilding an index reorganizes
   the storage of the index data (and table data in the case of a clustered
   index) to remove fragmentation. This can improve disk performance by
   reducing the number of page reads required to obtain the requested
   DBCC INDEXDEFRAG - Defragments clustered and secondary indexes of
   the specified table or view.
39.       What is sorting and what is the difference between sorting
   & clustered indexes?
   The ORDER BY clause sorts query results by one or more columns up to
   8,060 bytes. This will happen by the time when we retrieve data from
   database. Clustered indexes physically sorting data, while
   inserting/updating the table.
40.       What are statistics, under what circumstances they go out
   of date, how do you update them?
   Statistics determine the selectivity of the indexes. If an indexed column
   has unique values then the selectivity of that index is more, as opposed
   to an index with non-unique values. Query optimizer uses these indexes
   in determining whether to choose an index or not while executing a
   Some situations under which you should update statistics:
   1) If there is significant change in the key values in the index
   2) If a large amount of data in an indexed column has been added,
   changed, or removed (that is, if the distribution of key values has
   changed), or the table has been truncated using the TRUNCATE TABLE
   statement and then repopulated
   3) Database is upgraded from a previous version
41.       What is fillfactor? What is the use of it ? What happens
   when we ignore it? When you should use low fill factor?

                             Page 97 of 165
  When you create a clustered index, the data in the table is stored in the
  data pages of the database according to the order of the values in the
  indexed columns. When new rows of data are inserted into the table or
  the values in the indexed columns are changed, Microsoft® SQL
  Server™ 2000 may have to reorganize the storage of the data in the
  table to make room for the new row and maintain the ordered storage of
  the data. This also applies to nonclustered indexes. When data is added
  or changed, SQL Server may have to reorganize the storage of the data
  in the nonclustered index pages. When a new row is added to a full index
  page, SQL Server moves approximately half the rows to a new page to
  make room for the new row. This reorganization is known as a page
  split. Page splitting can impair performance and fragment the storage of
  the data in a table.
  When creating an index, you can specify a fill factor to leave extra gaps
  and reserve a percentage of free space on each leaf level page of the
  index to accommodate future expansion in the storage of the table's
  data and reduce the potential for page splits. The fill factor value is a
  percentage from 0 to 100 that specifies how much to fill the data pages
  after the index is created. A value of 100 means the pages will be full
  and will take the least amount of storage space. This setting should be
  used only when there will be no changes to the data, for example, on a
  read-only table. A lower value leaves more empty space on the data
  pages, which reduces the need to split data pages as indexes grow but
  requires more storage space. This setting is more appropriate when
  there will be changes to the data in the table.

42.    What are the data types in SQL

  bigint           Binary        bit            char               cursor
  datetime         Decimal       float          image              int
  money            Nchar         ntext          nvarchar           real
  smalldatetime    Smallint      smallmoney     text               timestamp
  tinyint          Varbinary     Varchar        uniqueidentifier

43.      Difference between char and nvarchar / char and varchar
   char[(n)] - Fixed-length non-Unicode character data with length of n
   bytes. n must be a value from 1 through 8,000. Storage size is n bytes.
   The SQL-92 synonym for char is character.
   nvarchar(n) - Variable-length Unicode character data of n characters. n
   must be a value from 1 through 4,000. Storage size, in bytes, is two
   times the number of characters entered. The data entered can be 0
   characters in length. The SQL-92 synonyms for nvarchar are national
   char varying and national character varying.
   varchar[(n)] - Variable-length non-Unicode character data with length of
   n bytes. n must be a value from 1 through 8,000. Storage size is the
   actual length in bytes of the data entered, not n bytes. The data entered

                               Page 98 of 165
   can be 0 characters in length. The SQL-92 synonyms for varchar are
   char varying or character varying.
44.       GUID datasize?
45.       How GUID becoming unique across machines?
   To ensure uniqueness across machines, the ID of the network card is
   used (among others) to compute the number.
46.       What is the difference between text and image data type?
   Text and image. Use text for character data if you need to store more
   than 255 characters in SQL Server 6.5, or more than 8000 in SQL Server
   7.0. Use image for binary large objects (BLOBs) such as digital images.
   With text and image data types, the data is not stored in the row, so the
   limit of the page size does not apply.All that is stored in the row is a
   pointer to the database pages that contain the data.Individual text,
   ntext, and image values can be a maximum of 2-GB, which is too long to
   store in a single data row.

47.      What are joins?
   Sometimes we have to select data from two or more tables to make our
   result complete. We have to perform a join.
48.      How many types of Joins?
   Joins can be categorized as:
       Inner joins (the typical join operation, which uses some
         comparison operator like = or <>). These include equi-joins and
         natural joins.
         Inner joins use a comparison operator to match rows from two
         tables based on the values in common columns from each table.
         For example, retrieving all rows where the student identification
         number is the same in both the students and courses tables.
       Outer joins. Outer joins can be a left, a right, or full outer join.
         Outer joins are specified with one of the following sets of keywords
         when they are specified in the FROM clause:
             LEFT JOIN or LEFT OUTER JOIN -The result set of a left outer
               join includes all the rows from the left table specified in the
               LEFT OUTER clause, not just the ones in which the joined
               columns match. When a row in the left table has no
               matching rows in the right table, the associated result set
               row contains null values for all select list columns coming
               from the right table.
             RIGHT JOIN or RIGHT OUTER JOIN - A right outer join is the
               reverse of a left outer join. All rows from the right table are
               returned. Null values are returned for the left table any time
               a right table row has no matching row in the left table.
             FULL JOIN or FULL OUTER JOIN - A full outer join returns all
               rows in both the left and right tables. Any time a row has no
               match in the other table, the select list columns from the
               other table contain null values. When there is a match

                             Page 99 of 165
                between the tables, the entire result set row contains data
                values from the base tables.
       Cross joins - Cross joins return all rows from the left table, each
          row from the left table is combined with all rows from the right
          table. Cross joins are also called Cartesian products. (A
          Cartesian join will get you a Cartesian product. A Cartesian join is
          when you join every row of one table to every row of another
          table. You can also get one by joining every row of a table to every
          row of itself.)
49.       What is self join?
   A table can be joined to itself in a self-join.
50.       What are the differences between UNION and JOINS?
   A join selects columns from 2 or more tables. A union selects rows.
51.       Can I improve performance by using the ANSI-style joins
   instead of the old-style joins?
   Code Example 1:
   from sysobjects o, sysindexes i
   where =
   Code Example 2:
   from sysobjects o inner join sysindexes i
   on =
   You will not get any performance gain by switching to the ANSI-style
   JOIN syntax.
   Using the ANSI-JOIN syntax gives you an important advantage: Because
   the join logic is cleanly separated from the filtering criteria, you can
   understand the query logic more quickly.
   The SQL Server old-style JOIN executes the filtering conditions before
   executing the joins, whereas the ANSI-style JOIN reverses this
   procedure (join logic precedes filtering).
   Perhaps the most compelling argument for switching to the ANSI-style
   JOIN is that Microsoft has explicitly stated that SQL Server will not
   support the old-style OUTER JOIN syntax indefinitely. Another important
   consideration is that the ANSI-style JOIN supports query constructions
   that the old-style JOIN syntax does not support.
52.       What is derived table?
   Derived tables are SELECT statements in the FROM clause referred to by
   an alias or a user-specified name. The result set of the SELECT in the
   FROM clause forms a table used by the outer SELECT statement. For
   example, this SELECT uses a derived table to find if any store carries all
   book titles in the pubs database:
   SELECT ST.stor_id, ST.stor_name
   FROM stores AS ST,
       (SELECT stor_id, COUNT(DISTINCT title_id) AS title_count
        FROM sales
        GROUP BY stor_id
       ) AS SA
   WHERE ST.stor_id = SA.stor_id

                             Page 100 of 165
   AND SA.title_count = (SELECT COUNT(*) FROM titles)

53.      What is Stored procedure?
   A stored procedure is a set of Structured Query Language (SQL)
   statements that you assign a name to and store in a database in
   compiled form so that you can share it between a number of programs.
       They allow modular programming.
       They allow faster execution.
       They can reduce network traffic.
       They can be used as a security mechanism.
54.      What are the different types of Storage Procedure?
       . Temporary Stored Procedures - SQL Server supports two types of
         temporary procedures: local and global. A local temporary
         procedure is visible only to the connection that created it. A global
         temporary procedure is available to all connections. Local
         temporary procedures are automatically dropped at the end of the
         current session. Global temporary procedures are dropped at the
         end of the last session using the procedure. Usually, this is when
         the session that created the procedure ends. Temporary
         procedures named with # and ## can be created by any user.
      a. System stored procedures are created and stored in the master
         database and have the sp_ prefix.(or xp_) System stored
         procedures can be executed from any database without having to
         qualify the stored procedure name fully using the database name
         master. (If any user-created stored procedure has the same name
         as a system stored procedure, the user-created stored procedure
         will never be executed.)
      b. Automatically Executing Stored Procedures - One or more stored
         procedures can execute automatically when SQL Server starts. The
         stored procedures must be created by the system administrator
         and executed under the sysadmin fixed server role as a
         background process. The procedure(s) cannot have any input
      c. User stored procedure
55.      How do I mark the stored procedure to automatic
   You can use the sp_procoption system stored procedure to mark the
   stored procedure to automatic execution when the SQL Server will start.
   Only objects in the master database owned by dbo can have the startup
   setting changed and this option is restricted to objects that have no
   USE master
   EXEC sp_procoption 'indRebuild', 'startup', 'true')
56.      How can you optimize a stored procedure?
57.      How will know whether the SQL statements are executed?
   When used in a stored procedure, the RETURN statement can specify an
   integer value to return to the calling application, batch, or procedure. If
   no value is specified on RETURN, a stored procedure returns the value

                             Page 101 of 165
   0. The stored procedures return a value of 0 when no errors were
   encountered. Any nonzero value indicates an error occurred.
58.       Why one should not prefix user stored procedures with sp_?
   It is strongly recommended that you do not create any stored
   procedures using sp_ as a prefix. SQL Server always looks for a stored
   procedure beginning with sp_ in this order:
       0. The stored procedure in the master database.
       1. The stored procedure based on any qualifiers provided (database
          name or owner).
       2. The stored procedure using dbo as the owner, if one is not

   Therefore, although the user-created stored procedure prefixed with sp_
   may exist in the current database, the master database is always
   checked first, even if the stored procedure is qualified with the database

59.       What can cause a Stored procedure execution plan to
   become invalidated and/or fall out of cache?
       0. Server restart
       1. Plan is aged out due to low use
       2. DBCC FREEPROCCACHE (sometime desired to force it)
60.       When do one need to recompile stored procedure?
   if a new index is added from which the stored procedure might benefit,
   optimization does not automatically happen (until the next time the
   stored procedure is run after SQL Server is restarted).
61.       SQL Server provides three ways to recompile a stored
        The sp_recompile system stored procedure forces a recompile of
          a stored procedure the next time it is run.
        Creating a stored procedure that specifies the WITH RECOMPILE
          option in its definition indicates that SQL Server does not cache a
          plan for this stored procedure; the stored procedure is recompiled
          each time it is executed. Use the WITH RECOMPILE option when
          stored procedures take parameters whose values differ widely
          between executions of the stored procedure, resulting in different
          execution plans to be created each time. Use of this option is
          uncommon, and causes the stored procedure to execute more
          slowly because the stored procedure must be recompiled each
          time it is executed.
        You can force the stored procedure to be recompiled by specifying
          the WITH RECOMPILE option when you execute the stored
          procedure. Use this option only if the parameter you are supplying
          is atypical or if the data has significantly changed since the stored
          procedure was created.
62.       How to find out which stored procedure is recompiling?
   How to stop stored procedures from recompiling?
63.       I have Two Stored Procedures SP1 and SP2 as given below.
   How the Transaction works, whether SP2 Transaction succeeds

                             Page 102 of 165
   or fails?

   commit tran
   Both will get roll backed.
      commit tran
   Both will get roll backed.
65.       How will you handle Errors in Sql Stored Procedure?
   INSERT NonFatal VALUES (@Column2)
   IF @@ERROR <>0
     PRINT 'Error Occured'
66.       How will you raise an error in sql?
   RAISERROR - Returns a user-defined error message and sets a system
   flag to record that an error has occurred. Using RAISERROR, the client
   can either retrieve an entry from the sysmessages table or build a
   message dynamically with user-specified severity and state information.
   After the message is defined it is sent back to the client as a server error
67.       I have a stored procedure like
   commit tran
   create table a()
   insert into table b
   rollback tran
   what will be the result? Is table created? data will be inserted in table b?
68.       What do you do when one procedure is blocking the other?

                             Page 103 of 165
69.      How you will return XML from Stored Procedure?
   You use the FOR XML clause of the SELECT statement, and within the
   FOR XML clause you specify an XML mode: RAW, AUTO, or EXPLICIT.
70.      What are the differences between RAW, AUTO and Explicit
   modes in retrieving data from SQL Server in XML format?
71.      Can a Stored Procedure call itself (recursive). If so then up
   to what level and can it be control?
   Stored procedures are nested when one stored procedure calls another.
   You can nest stored procedures up to 32 levels. The nesting level
   increases by one when the called stored procedure begins execution and
   decreases by one when the called stored procedure completes execution.
   Attempting to exceed the maximum of 32 levels of nesting causes the
   whole calling stored procedure chain to fail. The current nesting level for
   the stored procedures in execution is stored in the @@NESTLEVEL
   USE master
   IF OBJECT_ID('dbo.sp_calcfactorial') IS NOT NULL
   DROP PROC dbo.sp_calcfactorial
   CREATE PROC dbo.sp_calcfactorial
   @base_number int, @factorial int OUT
   DECLARE @previous_number int
   IF (@base_number<2) SET @factorial=1 -- Factorial of 0 or 1=1
   SET @previous_number=@base_number-1
   EXEC dbo.sp_calcfactorial @previous_number, @factorial OUT --
   Recursive call
   IF (@factorial=-1) RETURN(-1) -- Got an error, return
   SET @factorial=@factorial*@base_number

   calling proc.
   DECLARE @factorial int
   EXEC dbo.sp_calcfactorial 4, @factorial OUT
   SELECT @factorial
72.       Nested Triggers
   Triggers are nested when a trigger performs an action that initiates
   another trigger, which can initiate another trigger, and so on. Triggers
   can be nested up to 32 levels, and you can control whether triggers can
   be nested through the nested triggers server configuration option.
73.       What is an extended stored procedure? Can you instantiate
   a COM object by using T-SQL?
   An extended stored procedure is a function within a DLL (written in a

                             Page 104 of 165
   programming language like C, C++ using Open Data Services (ODS)
   API) that can be called from T-SQL, just the way we call normal stored
   procedures using the EXEC statement.
74.      Difference between view and stored procedure?
   Views can have only select statements (create, update, truncate, delete
   statements are not allowed) Views cannot have ―select into‖, ―Group by‖
   ―Having‖, ‖Order by‖
75.      What is a Function & what are the different user defined
   Function is a saved Transact-SQL routine that returns a value. User-
   defined functions cannot be used to perform a set of actions that modify
   the global database state. User-defined functions, like system functions,
   can be invoked from a query. They also can be executed through an
   EXECUTE statement like stored procedures.
      0. Scalar Functions
         Functions are scalar-valued if the RETURNS clause specified one of
         the scalar data types
      1. Inline Table-valued Functions
         If the RETURNS clause specifies TABLE with no accompanying
         column list, the function is an inline function.
      2. Multi-statement Table-valued Functions
         If the RETURNS clause specifies a TABLE type with columns and
         their data types, the function is a multi-statement table-valued
76.      What are the difference between a function and a stored
      0. Functions can be used in a select statement where as procedures
      1. Procedure takes both input and output parameters but Functions
         takes only input parameters
      2. Functions cannot return values of type text, ntext, image &
         timestamps where as procedures can
      3. Functions can be used as user defined datatypes in create table
         but procedures cannot
         ***Eg:-create table <tablename>(name varchar(10),salary
         Here getsal is a user defined function which returns a salary type,
         when table is created no storage is allotted for salary type, and
         getsal function is also not executed, But when we are fetching
         some values from this table, getsal function get‘s executed and the
         Type is returned as the result set.
77.      How to debug a stored procedure?

78.      What is Trigger? What is its use? What are the types of
   Triggers? What are the new kinds of triggers in sql 2000?
   Triggers are a special class of stored procedure defined to execute
   automatically when an UPDATE, INSERT, or DELETE statement is issued

                            Page 105 of 165
  against a table or view. Triggers are powerful tools that sites can use to
  enforce their business rules automatically when data is modified.
  The CREATE TRIGGER statement can be defined with the FOR UPDATE,
  FOR INSERT, or FOR DELETE clauses to target a trigger to a specific
  class of data modification actions. When FOR UPDATE is specified, the IF
  UPDATE (column_name) clause can be used to target a trigger to
  updates affecting a particular column.
  You can use the FOR clause to specify when a trigger is executed:
      AFTER (default) - The trigger executes after the statement that
        triggered it completes. If the statement fails with an error, such as
        a constraint violation or syntax error, the trigger is not executed.
        AFTER triggers cannot be specified for views.
      INSTEAD OF -The trigger executes in place of the triggering action.
        INSTEAD OF triggers can be specified on both tables and views.
        You can define only one INSTEAD OF trigger for each triggering
        action (INSERT, UPDATE, and DELETE). INSTEAD OF triggers can
        be used to perform enhance integrity checks on the data values
        supplied in INSERT and UPDATE statements. INSTEAD OF triggers
        also let you specify actions that allow views, which would normally
        not support updates, to be updatable.
        An INSTEAD OF trigger can take actions such as:
             Ignoring parts of a batch.
             Not processing a part of a batch and logging the problem
             Taking an alternative action if an error condition is

  In SQL Server 6.5 you could define only 3 triggers per table, one for
  INSERT, one for UPDATE and one for DELETE. From SQL Server 7.0
  onwards, this restriction is gone, and you could create multiple triggers
  per each action. But in 7.0 there's no way to control the order in which
  the triggers fire. In SQL Server 2000 you could specify which trigger
  fires first or fires last using sp_settriggerorder.
  Till SQL Server 7.0, triggers fire only after the data modification
  operation happens. So in a way, they are called post triggers. But in SQL
  Server 2000 you could create pre triggers also.

79.      When should one use "instead of Trigger"? Example
   PrimaryKey int IDENTITY(1,1),
   Color nvarchar(10) NOT NULL,
   Material nvarchar(10) NOT NULL,
   ComputedCol AS (Color + Material)

  --Create a view that contains all columns from the base table.
  CREATE VIEW InsteadView

                            Page 106 of 165
   AS SELECT PrimaryKey, Color, Material, ComputedCol
   FROM BaseTable

   --Create an INSTEAD OF INSERT trigger on tthe view.
   CREATE TRIGGER InsteadTrigger on InsteadView
   --Build an INSERT statement ignoring inserrted.PrimaryKey and
   INSERT INTO BaseTable
   SELECT Color, Material
   FROM inserted

   -- can insert value to basetable by this insert into
   basetable(color,material) values ('red','abc')

   -- insert into InsteadView(color,material)) values ('red','abc') can't do
   -- It will give error "'PrimaryKey' iin table 'InsteadView' cannot be null."

   -- can insert value through table by this<
   insert into InsteadView values (1,'red','abc',1) --PrimaryKey,
   ComputedCol wont take values from here
80.       Difference between trigger and stored procedure?
   Trigger will get execute automatically when an UPDATE, INSERT, or
   DELETE statement is issued against a table or view.
   We have to call stored procedure manually, or it can execute automatic
   when the SQL Server starts (You can use the sp_procoption system
   stored procedure to mark the stored procedure to automatic execution
   when the SQL Server will start.
81.       The following trigger generates an e-mail whenever a new
   title is added.
   CREATE TRIGGER reminder
   ON titles
   EXEC master..xp_sendmail 'MaryM', 'New title, mention in the next
   report to distributors.'
82.       Drawback of trigger? Its alternative solution?
   Triggers are generally used to implement business rules, auditing.
   Triggers can also be used to extend the referential integrity checks, but
   wherever possible, use constraints for this purpose, instead of triggers,
   as constraints are much faster.


                              Page 107 of 165
83.      What are locks?
   Microsoft® SQL Server™ 2000 uses locking to ensure transactional
   integrity and database consistency. Locking prevents users from reading
   data being changed by other users, and prevents multiple users from
   changing the same data at the same time. If locking is not used, data
   within the database may become logically incorrect, and queries
   executed against that data may produce unexpected results.
84.      What are the different types of locks?
   SQL Server uses these resource lock modes.

   Lock mode Description
               Used for operations that do not change or update data (read-only
   Shared (S)
               operations), such as a SELECT statement.
               Used on resources that can be updated. Prevents a common form of
   Update (U) deadlock that occurs when multiple sessions are reading, locking, and
               potentially updating resources later.
               Used for data-modification operations, such as INSERT, UPDATE, or
               DELETE. Ensures that multiple updates cannot be made to the same
               resource at the same time.
               Used to establish a lock hierarchy. The types of intent locks are: intent
               shared (IS), intent exclusive (IX), and shared with intent exclusive (SIX).
               Used when an operation dependent on the schema of a table is executing.
   Schema      The types of schema locks are: schema modification (Sch-M) and schema
               stability (Sch-S).
   Bulk Update Used when bulk-copying data into a table and the TABLOCK hint is
   (BU)        specified.

85.       What is a dead lock? Give a practical sample? How you can
   minimize the deadlock situation? What is a deadlock and what is
   a live lock? How will you go about resolving deadlocks?
   Deadlock is a situation when two processes, each having a lock on one
   piece of data, attempt to acquire a lock on the other's piece. Each
   process would wait indefinitely for the other to release the lock, unless
   one of the user processes is terminated. SQL Server detects deadlocks
   and terminates one user's process.
   A livelock is one, where a request for an exclusive lock is repeatedly
   denied because a series of overlapping shared locks keeps interfering.
   SQL Server detects the situation after four denials and refuses further
   shared locks. (A livelock also occurs when read transactions monopolize
   a table or page, forcing a write transaction to wait indefinitely.)
86.       What is isolation level?
   An isolation level determines the degree of isolation of data between
   concurrent transactions. The default SQL Server isolation level is Read
   Committed. A lower isolation level increases concurrency, but at the
   expense of data correctness. Conversely, a higher isolation level ensures
   that data is correct, but can affect concurrency negatively. The isolation
   level required by an application determines the locking behavior SQL
   Server uses.
   SQL-92 defines the following isolation levels, all of which are supported
   by SQL Server:

                                 Page 108 of 165
         Read uncommitted (the lowest level where transactions are
          isolated only enough to ensure that physically corrupt data is not
         Read committed (SQL Server default level).
         Repeatable read.
         Serializable (the highest level, where transactions are completely
          isolated from one another).

        Isolation level         Dirty read     Nonrepeatable read      Phantom
   Read uncommitted       Yes                Yes                    Yes
   Read committed         No                 Yes                    Yes
   Repeatable read        No                 No                     Yes
   Serializable           No                 No                     No

87.       Uncommitted Dependency (Dirty Read) - Uncommitted
   dependency occurs when a second transaction selects a row that is being
   updated by another transaction. The second transaction is reading data
   that has not been committed yet and may be changed by the transaction
   updating the row. For example, an editor is making changes to an
   electronic document. During the changes, a second editor takes a copy
   of the document that includes all the changes made so far, and
   distributes the document to the intended audience.
   Inconsistent Analysis (Nonrepeatable Read) Inconsistent analysis occurs
   when a second transaction accesses the same row several times and
   reads different data each time. Inconsistent analysis is similar to
   uncommitted dependency in that another transaction is changing the
   data that a second transaction is reading. However, in inconsistent
   analysis, the data read by the second transaction was committed by the
   transaction that made the change. Also, inconsistent analysis involves
   multiple reads (two or more) of the same row and each time the
   information is changed by another transaction; thus, the term
   nonrepeatable read. For example, an editor reads the same document
   twice, but between each reading, the writer rewrites the document.
   When the editor reads the document for the second time, it has
   Phantom Reads Phantom reads occur when an insert or delete action is
   performed against a row that belongs to a range of rows being read by a
   transaction. The transaction's first read of the range of rows shows a row
   that no longer exists in the second or succeeding read, as a result of a
   deletion by a different transaction. Similarly, as the result of an insert by
   a different transaction, the transaction's second or succeeding read
   shows a row that did not exist in the original read. For example, an
   editor makes changes to a document submitted by a writer, but when
   the changes are incorporated into the master copy of the document by
   the production department, they find that new unedited material has
   been added to the document by the author. This problem could be
   avoided if no one could add new material to the document until the
   editor and production department finish working with the original

                                Page 109 of 165
88.      nolock? What is the difference between the REPEATABLE
   READ and SERIALIZE isolation levels?
   Locking Hints - A range of table-level locking hints can be specified
   using the SELECT, INSERT, UPDATE, and DELETE statements to direct
   Microsoft® SQL Server 2000 to the type of locks to be used. Table-level
   locking hints can be used when a finer control of the types of locks
   acquired on an object is required. These locking hints override the
   current transaction isolation level for the session.

     Locking hint                        Description
  HOLDLOCK          Hold a shared lock until completion of the transaction
                    instead of releasing the lock as soon as the required
                    table, row, or data page is no longer required.
                    HOLDLOCK is equivalent to SERIALIZABLE.
  NOLOCK            Do not issue shared locks and do not honor exclusive
                    locks. When this option is in effect, it is possible to
                    read an uncommitted transaction or a set of pages
                    that are rolled back in the middle of a read. Dirty
                    reads are possible. Only applies to the SELECT
  PAGLOCK           Use page locks where a single table lock would usually
                    be taken.
  READCOMMITTED     Perform a scan with the same locking semantics as a
                    transaction running at the READ COMMITTED isolation
                    level. By default, SQL Server 2000 operates at this
                    isolation level.
  READPAST          Skip locked rows. This option causes a transaction to
                    skip rows locked by other transactions that would
                    ordinarily appear in the result set, rather than block
                    the transaction waiting for the other transactions to
                    release their locks on these rows. The READPAST lock
                    hint applies only to transactions operating at READ
                    COMMITTED isolation and will read only past row-level
                    locks. Applies only to the SELECT statement.
  REPEATABLEREAD    Perform a scan with the same locking semantics as a
                    transaction running at the REPEATABLE READ
                    isolation level.
  ROWLOCK           Use row-level locks instead of the coarser-grained
                    page- and table-level locks.
  SERIALIZABLE      Perform a scan with the same locking semantics as a
                    transaction running at the SERIALIZABLE isolation
                    level. Equivalent to HOLDLOCK.
  TABLOCK           Use a table lock instead of the finer-grained row- or
                    page-level locks. SQL Server holds this lock until the
                    end of the statement. However, if you also specify
                    HOLDLOCK, the lock is held until the end of the
  TABLOCKX          Use an exclusive lock on a table. This lock prevents
                    others from reading or updating the table and is held
                    until the end of the statement or transaction.
  UPDLOCK           Use update locks instead of shared locks while reading
                    a table, and hold locks until the end of the statement

                             Page 110 of 165
                     or transaction. UPDLOCK has the advantage of
                     allowing you to read data (without blocking other
                     readers) and update it later with the assurance that
                     the data has not changed since you last read it.
   XLOCK             Use an exclusive lock that will be held until the end of
                     the transaction on all data processed by the
                     statement. This lock can be specified with either
                     PAGLOCK or TABLOCK, in which case the exclusive
                     lock applies to the appropriate level of granularity.

89.       For example, if the transaction isolation level is set to
   SERIALIZABLE, and the table-level locking hint NOLOCK is used with the
   SELECT statement, key-range locks typically used to maintain
   serializable transactions are not taken.
   USE pubs
   SELECT au_lname FROM authors WITH (NOLOCK)
90.       What is escalation of locks?
   Lock escalation is the process of converting a lot of low level locks (like
   row locks, page locks) into higher level locks (like table locks). Every
   lock is a memory structure too many locks would mean, more memory
   being occupied by locks. To prevent this from happening, SQL Server
   escalates the many fine-grain locks to fewer coarse-grain locks. Lock
   escalation threshold was definable in SQL Server 6.5, but from SQL
   Server 7.0 onwards it's dynamically managed by SQL Server.

91.      What is View? Use? Syntax of View?
   A view is a virtual table made up of data from base tables and other
   views, but not stored separately.
       Views simplify users perception of the database (can be used to
         present only the necessary information while hiding details in
         underlying relations)
       Views improve data security preventing undesired accesses
       Views facilite the provision of additional data independence
92.      Does the View occupy memory space?
93.      Can u drop a table if it has a view?
   Views or tables participating in a view created with the SCHEMABINDING
   clause cannot be dropped. If the view is not created using
   SCHEMABINDING, then we can drop the table.
94.      Why doesn't SQL Server permit an ORDER BY clause in the
   definition of a view?
   SQL Server excludes an ORDER BY clause from a view to comply with
   the ANSI SQL-92 standard. Because analyzing the rationale for this
   standard requires a discussion of the underlying structure of the

                              Page 111 of 165
         structured query language (SQL) and the mathematics upon which it is
         based, we can't fully explain the restriction here. However, if you need
         to be able to specify an ORDER BY clause in a view, consider using the
         following workaround:
         USE pubs
         CREATE VIEW AuthorsByName
         SELECT TOP 100 PERCENT *
         FROM authors
         ORDER BY au_lname, au_fname
         The TOP construct, which Microsoft introduced in SQL Server 7.0, is
         most useful when you combine it with the ORDER BY clause. The only
         time that SQL Server supports an ORDER BY clause in a view is when it
         is used in conjunction with the TOP keyword. (Note that the TOP
         keyword is a SQL Server extension to the ANSI SQL-92 standard.)

      95.        What is Transaction?
           A transaction is a sequence of operations performed as a single logical
           unit of work. A logical unit of work must exhibit four properties, called
           the ACID (Atomicity, Consistency, Isolation, and Durability) properties,
           to qualify as a transaction:
               Atomicity - A transaction must be an atomic unit of work; either
                 all of its data modifications are performed or none of them is
               Consistency - When completed, a transaction must leave all data
                 in a consistent state. In a relational database, all rules must be
                 applied to the transaction's modifications to maintain all data
                 integrity. All internal data structures, such as B-tree indexes or
                 doubly-linked lists, must be correct at the end of the transaction.
               Isolation - Modifications made by concurrent transactions must
                 be isolated from the modifications made by any other concurrent
                 transactions. A transaction either sees data in the state it was in
                 before another concurrent transaction modified it, or it sees the
                 data after the second transaction has completed, but it does not
                 see an intermediate state. This is referred to as serializability
                 because it results in the ability to reload the starting data and
                 replay a series of transactions to end up with the data in the same
                 state it was in after the original transactions were performed.
               Durability - After a transaction has completed, its effects are
                 permanently in place in the system. The modifications persist even
                 in the event of a system failure.
96.        After one Begin Transaction a truncate statement and a RollBack
   statements are there. Will it be rollbacked? Since the truncate
   statement does not perform logged operation how does it RollBack?
   It will rollback.

                                   Page 112 of 165
97.      Given a SQL like
   Begin Tran
     Select @@Rowcount
   Begin Tran
     Select @@Rowcount
   Begin Tran
     Select @@Rowcount
   Commit Tran
     Select @@Rowcount
     Select @@Rowcount
     Select @@Rowcount
   What is the value of @@Rowcount at each stmt levels?
   Ans : 0 – zero.
   @@ROWCOUNT - Returns the number of rows affected by the last statement.
   @@TRANCOUNT - Returns the number of active transactions for the current
   Each Begin Tran will add count, each commit will reduce count and ONE
   rollback will make it 0.

98.      What are the constraints for Table Constraints define rules
   regarding the values allowed in columns and are the standard
   mechanism for enforcing integrity. SQL Server 2000 supports five
   classes of constraints.
99.      There are 50 columns in a table. Write a query to get first 25
   Ans: Need to mention each column names.
100.     How to list all the tables in a particular database?
   USE pubs
101.     What are cursors? Explain different types of cursors. What are
   the disadvantages of cursors? How can you avoid cursors?
   Cursors allow row-by-row processing of the result sets.
   Types of cursors: Static, Dynamic, Forward-only, Keyset-driven.
   Disadvantages of cursors: Each time you fetch a row from the cursor, it results
   in a network roundtrip. Cursors are also costly because they require more
   resources and temporary storage (results in more IO operations). Further,
   there are restrictions on the SELECT statements that can be used with some
   types of cursors.
   How to avoid cursor:

                                  Page 113 of 165
     0.         Most of the times, set based operations can be used instead of
         cursors. Here is an example: If you have to give a flat hike to your
         employees using the following criteria:
         Salary between 30000 and 40000 -- 5000 hike
         Salary between 40000 and 55000 -- 7000 hike
         Salary between 55000 and 65000 -- 9000 hike
         In this situation many developers tend to use a cursor, determine each
         employee's salary and update his salary according to the above formula.
         But the same can be achieved by multiple update statements or can be
         combined in a single UPDATE statement as shown below:
         UPDATE tbl_emp SET salary =
         CASE WHEN salary BETWEEN 30000 AND 40000 THEN salary + 5000
         WHEN salary BETWEEN 40000 AND 55000 THEN salary + 7000
         WHEN salary BETWEEN 55000 AND 65000 THEN salary + 10000
     1.         You need to call a stored procedure when a column in a particular
         row meets certain condition. You don't have to use cursors for this. This
         can be achieved using WHILE loop, as long as there is a unique key to
         identify each row. For examples of using WHILE loop for row by row
         processing, check out the 'My code library' section of my site or search
         for WHILE.
102.     What is Dynamic Cursor? Suppose, I have a dynamic cursor
  attached to table in a database. I have another means by which I will
  modify the table. What do you think will the values in the cursor be?
  Dynamic cursors reflect all changes made to the rows in their result set when
  scrolling through the cursor. The data values, order, and membership of the
  rows in the result set can change on each fetch. All UPDATE, INSERT, and
  DELETE statements made by all users are visible through the cursor. Updates
  are visible immediately if they are made through the cursor using either an
  API function such as SQLSetPos or the Transact-SQL WHERE CURRENT OF
  clause. Updates made outside the cursor are not visible until they are
  committed, unless the cursor transaction isolation level is set to read
103.     What is DATEPART?
  Returns an integer representing the specified datepart of the specified date.
104.     Difference between Delete and Truncate?
  TRUNCATE TABLE is functionally identical to DELETE statement with no WHERE
  clause: both remove all rows in the table.
  (1) But TRUNCATE TABLE is faster and uses fewer system and transaction log
  resources than DELETE. The DELETE statement removes rows one at a time
  and records an entry in the transaction log for each deleted row. TRUNCATE
  TABLE removes the data by deallocating the data pages used to store the
  table's data, and only the page deallocations are recorded in the transaction
  (2) Because TRUNCATE TABLE is not logged, it cannot activate a trigger.
  (3) The counter used by an identity for new rows is reset to the seed for the
  column. If you want to retain the identity counter, use DELETE instead.
  Of course, TRUNCATE TABLE can be rolled back.

                                  Page 114 of 165
105.     Given a scenario where two operations, Delete Stmt and
  Truncate Stmt, where the Delete Statement was successful and the
  truncate stmt was failed. – Can u judge why?
106.     What are global variables? Tell me some of them?
  Transact-SQL global variables are a form of function and are now referred to
  as functions.
  ABS - Returns the absolute, positive value of the given numeric expression.
107.     What is DDL?
  Data definition language (DDL) statements are SQL statements that support
  the definition or declaration of database objects (for example, CREATE TABLE,
  You can use the ADO Command object to issue DDL statements. To
  differentiate DDL statements from a table or stored procedure name, set the
  CommandType property of the Command object to adCmdText. Because
  executing DDL queries with this method does not generate any recordsets,
  there is no need for a Recordset object.
108.     What is DML?
  Data Manipulation Language (DML), which is used to select, insert, update,
  and delete data in the objects defined using DDL
109.     What are keys in RDBMS? What is a primary key/ foreign key?
  There are two kinds of keys.
  A primary key is a set of columns from a table that are guaranteed to have
  unique values for each row of that table.
  Foreign keys are attributes of one table that have matching values in a
  primary key in another table, allowing for relationships between tables.
110.     What is the difference between Primary Key and Unique Key?
  Both primary key and unique key enforce uniqueness of the column on which
  they are defined. But by default primary key creates a clustered index on the
  column, where are unique creates a nonclustered index by default. Another
  major difference is that, primary key doesn't allow NULLs, but unique key
  allows one NULL only.
111.     Define candidate key, alternate key, composite key?
  A candidate key is one that can identify each row of a table uniquely.
  Generally a candidate key becomes the primary key of the table. If the table
  has more than one candidate key, one of them will become the primary key,
  and the rest are called alternate keys.
  A key formed by combining at least two or more columns is called composite
112.     What is the Referential Integrity?
  Referential integrity refers to the consistency that must be maintained
  between primary and foreign keys, i.e. every foreign key value must have a
  corresponding primary key value.
113.     What are defaults? Is there a column to which a default can't be
  A default is a value that will be used by a column, if no value is supplied to

                                 Page 115 of 165
  that column while inserting data. IDENTITY columns and timestamp columns
  can't have defaults bound to them.
114.     What is Query optimization? How is tuning a performance of
  query done?
115.     What is the use of trace utility?
116.     What is the use of shell commands? xp_cmdshell
  Executes a given command string as an operating-system command shell and
  returns any output as rows of text. Grants nonadministrative users
  permissions to execute xp_cmdshell.
117.     What is use of shrink database?
  Microsoft® SQL Server 2000 allows each file within a database to be shrunk to
  remove unused pages. Both data and transaction log files can be shrunk.
118.     If the performance of the query suddenly decreased where you
  will check?
119.     What is a pass-through query?
  Microsoft® SQL Server 2000 sends pass-through queries as un-interpreted
  query strings to an OLE DB data source. The query must be in a syntax the
  OLE DB data source will accept. A Transact-SQL statement uses the results
  from a pass-through query as though it is a regular table reference.
  This example uses a pass-through query to retrieve a result set from a
  Microsoft Access version of the Northwind sample database.
  FROM OpenRowset('Microsoft.Jet.OLEDB.4.0',
  'c:\northwind.mdb';'admin'; '',
  'SELECT CustomerID, CompanyName
  FROM Customers
  WHERE Region = ''WA'' ')
120.     How do you differentiate Local and Global Temporary table?
  You can create local and global temporary tables. Local temporary tables are
  visible only in the current session; global temporary tables are visible to all
  sessions. Prefix local temporary table names with single number sign
  (#table_name), and prefix global temporary table names with a double
  number sign (##table_name). SQL statements reference the temporary table
  using the value specified for table_name in the CREATE TABLE statement:
121.     How the Exists keyword works in SQL Server?
  USE pubs
  SELECT au_lname, au_fname
  FROM authors
  WHERE exists
    (SELECT *
    FROM publishers
    WHERE =
  When a subquery is introduced with the keyword EXISTS, it functions as an
  existence test. The WHERE clause of the outer query tests for the existence of
  rows returned by the subquery. The subquery does not actually produce any
  data; it returns a value of TRUE or FALSE.

                                      Page 116 of 165
122.     ANY?
  USE pubs
  SELECT au_lname, au_fname
  FROM authors
  WHERE city = ANY
  (SELECT city
  FROM publishers)
123.     to select date part only
  SELECT CONVERT(char(10),GetDate(),101)
  --to select time part only
  SELECT right(GetDate(),7)
124.     How can I send a message to user from the SQL Server?
  You can use the xp_cmdshell extended stored procedure to run net send
  command. This is the example to send the 'Hello' message to JOHN:
  EXEC master..xp_cmdshell "net send JOHN 'Hello'"
  To get net send message on the Windows 9x machines, you should run the
  WinPopup utility. You can place WinPopup in the Startup group under Program
125.     What is normalization? Explain different levels of normalization?
  Explain Third normalization form with an example?
  The process of refining tables, keys, columns, and relationships to create an
  efficient database is called normalization. This should eliminates unnecessary
  duplication and provides a rapid search path to all necessary information.
  Some of the benefits of normalization are:
               Data integrity (because there is no redundant, neglected data)
               Optimized queries (because normalized tables produce rapid,
         efficient joins)
               Faster index creation and sorting (because the tables have fewer
               Faster UPDATE performance (because there are fewer indexes per
               Improved concurrency resolution (because table locks will affect
         less data)
               Eliminate redundancy

  There are a few rules for database normalization. Each rule is called a "normal
  form." If the first rule is observed, the database is said to be in "first normal
  form." If the first three rules are observed, the database is considered to be in
  "third normal form." Although other levels of normalization are possible, third
  normal form is considered the highest level necessary for most applications.

     6.          First Normal Form (1NF)
                      Eliminate repeating groups in individual tables
                      Create a separate table for each set of related data.
                      Identify each set of related data with a primary key.

          Do not use multiple fields in a single table to store similar data.

                         Subordinate1   Subordinate2    Subordinate3   Subordinate4

                                    Page 117 of 165
     Bob            Jim              Mary         Beth
     Mary           Mike             Jason        Carol          Mark
     Jim            Alan

     Eliminate duplicative columns from the same table. Clearly, the
     Subordinate1-Subordinate4 columns are duplicative. What happens
     when we need to add or remove a subordinate?

     Bob            Jim, Mary, Beth
     Mary           Mike, Jason, Carol, Mark
     Jim            Alan

     This solution is closer, but it also falls short of the mark. The
     subordinates column is still duplicative and non-atomic. What happens
     when we need to add or remove a subordinate? We need to read and
     write the entire contents of the table. That‘s not a big deal in this
     situation, but what if one manager had one hundred employees? Also, it
     complicates the process of selecting data from the database in future

     Bob       Jim
     Bob       Mary
     Bob       Beth
     Mary      Mike
     Mary      Jason
     Mary      Carol
     Mary      Mark
     Jim       Alan

7.          Second Normal Form (2NF)
                 Create separate tables for sets of values that apply to
            multiple records.
                 Relate these tables with a foreign key.

     Records should not depend on anything other than a table's primary key
     (a compound key, if necessary).
     For example, consider a customer's address in an accounting system.
     The address is needed by the Customers table, but also by the Orders,
     Shipping, Invoices, Accounts Receivable, and Collections tables. Instead
     of storing the customer's address as a separate entry in each of these
     tables, store it in one place, either in the Customers table or in a
     separate Addresses table.

8.          Third Normal Form (3NF)
                Eliminate fields that do not depend on the key.

     Values in a record that are not part of that record's key do not belong in
     the table. In general, any time the contents of a group of fields may
     apply to more than a single record in the table, consider placing those
                                Page 118 of 165
     fields in a separate table.
     For example, in an Employee Recruitment table, a candidate's university
     name and address may be included. But you need a complete list of
     universities for group mailings. If university information is stored in the
     Candidates table, there is no way to list universities with no current
     candidates. Create a separate Universities table and link it to the
     Candidates table with a university code key.
     Another Example :

     MemberId           Name                     Company    CompanyLoc
     1                  John Smith               ABC        Alabama
     2                  Dave Jones               MCI        Florida

     The Member table satisfies first normal form - it contains no repeating
     groups. It satisfies second normal form - since it doesn't have a
     multivalued key. But the key is MemberID, and the company name and
     location describe only a company, not a member. To achieve third
     normal form, they must be moved into a separate table. Since they
     describe a company, CompanyCode becomes the key of the new
     "Company" table.

     The motivation for this is the same for second normal form: we want to
     avoid update and delete anomalies. For example, suppose no members
     from the IBM were currently stored in the database. With the previous
     design, there would be no record of its existence, even though 20 past
     members were from IBM!
     Member Table

     MemberId           Name                     CID
     1                  John Smith               1
     2                  Dave Jones               2

     Company Table

     CId                Name                     Location
     1                  ABC                      Alabama
     2                  MCI                      Florida

9.       Boyce-Codd Normal Form (BCNF)
   A relation is in Boyce/Codd normal form if and only if the only
   determinants are candidate key. Its a different version of 3NF, indeed,
   was meant to replace it. [A determinant is any attribute on which some
   other attribute is (fully) functionally dependent.]
10.      4th Normal Form (4NF)
   A table is in 4NF if it is in BCNF and if it has no multi-valued
   dependencies. This applies primarily to key-only associative tables, and
   appears as a ternary relationship, but has incorrectly merged 2 distinct,
   independent relationships.
   Eg: This could be any 2 M:M relationships from a single entity. For

                               Page 119 of 165
        instance, a member could know many software tools, and a software
        tool may be used by many members. Also, a member could have
        recommended many books, and a book could be recommended by many

        Software      member              Book

     11.       The correct solution, to cause the model to be in 4th normal form,
        is to ensure that all M:M relationships are resolved independently if they
        are indeed independent.

        Software     membersoftware     member          memberBook        book

     12.      5th Normal Form (5NF)(PJNF)
        A table is in 5NF, also called "Projection-Join Normal Form", if it is in 4NF
        and if every join dependency in the table is a consequence of the
        candidate keys of the table.
     13.      Domain/key normal form (DKNF). A key uniquely identifies
        each row in a table. A domain is the set of permissible values for an
        attribute. By enforcing key and domain restrictions, the database is
        assured of being freed from modification anomalies. DKNF is the
        normalization level that most designers aim to achieve.

  Remember, these normalization guidelines are cumulative. For a database to
  be in 2NF, it must first fulfill all the criteria of a 1NF database.

126.    If a database is normalized by 3 NF then how many number of
  tables it should contain in minimum? How many minimum if 2NF and 1
127.    What is denormalization and when would you go for it?
  As the name indicates, denormalization is the reverse process of
  normalization. It's the controlled introduction of redundancy in to the database
  design. It helps improve the query performance as the number of joins could
  be reduced.
128.    How can I randomly sort query results?
  To randomly order rows, or to return x number of randomly chosen rows, you
  can use the RAND function inside the SELECT statement. But the RAND
  function is resolved only once for the entire query, so every row will get same
  value. You can use an ORDER BY clause to sort the rows by the result from the
  NEWID function, as the following code shows:
  FROM Northwind..Orders
129.    sp_who
  Provides information about current Microsoft® SQL Server™ users and
  processes. The information returned can be filtered to return only those
  processes that are not idle.

                                  Page 120 of 165
130.    Have you worked on Dynamic SQL? How will You handled “
  (Double Quotes) in Dynamic SQL?
131.    How to find dependents of a table?
  Verify dependencies with sp_depends before dropping an object
132.    What is the difference between a CONSTRAINT AND RULE?
  Rules are a backward-compatibility feature that perform some of the same
  functions as CHECK constraints. CHECK constraints are the preferred, standard
  way to restrict the values in a column. CHECK constraints are also more
  concise than rules; there can only be one rule applied to a column, but
  multiple CHECK constraints can be applied. CHECK constraints are specified as
  part of the CREATE TABLE statement, while rules are created as separate
  objects and then bound to the column.
133.    How to call a COM dll from SQL Server 2000?

  sp_OACreate - Creates an instance of the OLE object on an instance of
  Microsoft® SQL Server
  sp_OACreate progid, | clsid,
     objecttoken OUTPUT
     [ , context ]

  context - Specifies the execution context in which the newly created OLE
  object runs. If specified, this value must be one of the following:
  1 = In-process (.dll) OLE server only
  4 = Local (.exe) OLE server only
  5 = Both in-process and local OLE server allowed


  A. Use Prog ID - This example creates a SQL-DMO SQLServer object by using its ProgID.

  DECLARE @object int
  DECLARE @hr int
  DECLARE @src varchar(255), @desc varchar(255)
  EXEC @hr = sp_OACreate 'SQLDMO.SQLServer', @object OUT
  IF @hr <> 0
    EXEC sp_OAGetErrorInfo @object, @src OUT, @desc OUT
    SELECT hr=convert(varbinary(4),@hr), Source=@src, Description=@desc

  B. Use CLSID - This example creates a SQL-DMO SQLServer object by using its

  DECLARE @object int
  DECLARE @hr int
  DECLARE @src varchar(255), @desc varchar(255)
  EXEC @hr = sp_OACreate '{00026BA1-0000-0000-C000-000000000046}',
     @object OUT
  IF @hr <> 0

                                             Page 121 of 165
    EXEC sp_OAGetErrorInfo @object, @src OUT, @desc OUT
    SELECT hr=convert(varbinary(4),@hr), Source=@src, Description=@desc

134.    Difference between sysusers and syslogins?
  sysusers - Contains one row for each Microsoft® Windows user, Windows
  group, Microsoft SQL Server™ user, or SQL Server role in the database.
  syslogins - Contains one row for each login account.
135.    What is the row size in SQL Server 2000?
  8060 bytes.
136.    How will you find structure of table, all tables/views in one db, all
  //structure of table
  sp_helpdb tbl_emp

  //list of all databases
  SELECT * FROM master.dbo.sysdatabases

  //details about database pubs. .mdf, .ldf file locations, size of database
  sp_helpdb pubs

  //lists all tables under current database
  SELECT * FROM information_schema.tables WHERE (table_type = 'base table')
  SELECT * FROM sysobjects WHERE type = 'U' //faster
137.     B-tree indexes or doubly-linked lists?
138.     What is the system function to get the current user's user id?
  USER_ID(). Also check out other system functions like USER_NAME(),
139.     What are the series of steps that happen on execution of a query
  in a Query Analyzer?
  1) Syntax checking 2) Parsing 3) Execution plan
140.     Which event (Check constraints, Foreign Key, Rule, trigger,
  Primary key check) will be performed last for integrity check?
  Identity Insert Check
  Nullability constraint
  Data type check
  Instead of trigger
  Primary key
  Check constraint
  Foreign key
  DML Execution (update statements)
  After Trigger

                                    Page 122 of 165
141.     How will you show many to many relation in sql?
  Create 3rd table with 2 columns which having one to many relation to these
142.     When a query is sent to the database and an index is not being
  used, what type of execution is taking place?
  A table scan.
143.     What is #, ##, @, @@ means?
  @@ - System variables
  @ - user defined variables
144.     What is the difference between a Local temporary table and a
  Global temporary table? How is each one denoted?
  Local temporary table will be accessible to only current user session, its name
  will be preceded with a single hash (#mytable)
  Global temporary table will be accessible to all users, & it will be dropped only
  after ending of all active connections, its name will be preceded with double
  hash (##mytable)
145.     What is covered queries in SQL Server?
146.     What is HASH JOIN, MERGE JOIN?


   Have you ever used DBCC command? Give an example for it.
   The Transact-SQL programming language provides DBCC statements that act
   as Database Console Commands for Microsoft® SQL Serve 2000. These
   statements check the physical and logical consistency of a database. Many
   DBCC statements can fix detected problems. Database Console Command
   statements are grouped into these categories.

   Statement category                                               Perform
   Maintenance            Maintenance tasks on a database, index, or filegroup.
   Miscellaneous          Miscellaneous tasks such as enabling row-level locking or removing a dynamic-link l
   statements             (DLL) from memory.
   Status statements      Status checks.
   Validation statements Validation operations on a database, table, index, catalog, filegroup, system tables,
                         allocation of database pages.

148.     How do you use DBCC statements to monitor various aspects of a
  SQL server installation?
149.     What is the output of DBCC Showcontig statement?
  Displays fragmentation information for the data and indexes of the specified
150.     How do I reset the identity column?
  You can use the DBCC CHECKIDENT statement, if you want to reset or reseed
  the identity column. For example, if you need to force the current identity
  value in the jobs table to a value of 100, you can use the following:
                                           Page 123 of 165
  USE pubs
151.   About SQL Command line executables


152.     What is DTC?
  The Microsoft Distributed Transaction Coordinator (MS DTC) is a transaction
  manager that allows client applications to include several different sources of
  data in one transaction. MS DTC coordinates committing the distributed
  transaction across all the servers enlisted in the transaction.
153.     What is DTS? Any drawbacks in using DTS?
  Microsoft® SQL Server™ 2000 Data Transformation Services (DTS) is a set of
  graphical tools and programmable objects that lets you extract, transform, and
  consolidate data from disparate sources into single or multiple destinations.
154.     What is BCP?
  The bcp utility copies data between an instance of Microsoft® SQL Server™
  2000 and a data file in a user-specified format.
  C:\Documents and Settings\sthomas>bcp
  usage: bcp {dbtable | query} {in | out | queryout | format} datafile
  [-m maxerrors] [-f formatfile] [-e errfile]
  [-F firstrow] [-L lastrow] [-b batchsize]
  [-n native type] [-c character type] [-w wide character type]
  [-N keep non-text native] [-V file format version] [-q quoted identifier]
  [-C code page specifier] [-t field terminator] [-r row terminator]
  [-i inputfile] [-o outfile] [-a packetsize]
  [-S server name] [-U username] [-P password]
  [-T trusted connection] [-v version] [-R regional enable]
                                 Page 124 of 165
  [-k keep null values] [-E keep identity values]
  [-h "load hints"]
155.     How can I create a plain-text flat file from SQL Server as input to
  another application?
  One of the purposes of Extensible Markup Language (XML) is to solve
  challenges like this, but until all applications become XML-enabled, consider
  using our faithful standby, the bulk copy program (bcp) utility. This utility can
  do more than just dump a table; bcp also can take its input from a view
  instead of from a table. After you specify a view as the input source, you can
  limit the output to a subset of columns or to a subset of rows by selecting
  appropriate filtering (WHERE and HAVING) clauses.
  More important, by using a view, you can export data from multiple joined
  tables. The only thing you cannot do is specify the sequence in which the rows
  are written to the flat file, because a view does not let you include an ORDER
  BY clause in it unless you also use the TOP keyword.
  If you want to generate the data in a particular sequence or if you cannot
  predict the content of the data you want to export, be aware that in addition
  to a view, bcp also supports using an actual query. The only "gotcha" about
  using a query instead of a table or view is that you must specify queryout in
  place of out in the bcp command line.
  For example, you can use bcp to generate from the pubs database a list of
  authors who reside in California by writing the following code:
  bcp "SELECT * FROM pubs..authors WHERE state = 'CA'" queryout
  c:\CAauthors.txt -c -T -S
156.     What are the different ways of moving data/databases between
  servers and databases in SQL Server?
  There are lots of options available, you have to choose your option depending
  upon your requirements. Some of the options you have are:
  BACKUP/RESTORE, detaching and attaching databases, replication, DTS, BCP,
  logshipping, INSERT...SELECT, SELECT...INTO, creating INSERT scripts to
  generate data.
157.     How will I export database?
  Through DTS - Import/Export wizard
  Backup - through Complete/Differential/Transaction Log
158.     How to export database at a particular time, every week?
  Backup - Schedule
  DTS - Schedule
  Jobs - create a new job
159.     How do you load large data to the SQL server database?
160.     How do you transfer data from text file to database (other than
161.     What is OSQL and ISQL utility?
  The osql utility allows you to enter Transact-SQL statements, system
  procedures, and script files. This utility uses ODBC to communicate with the
  The isql utility allows you to enter Transact-SQL statements, system
  procedures, and script files; and uses DB-Library to communicate with

                                  Page 125 of 165
  Microsoft® SQL Server™ 2000.
  All DB-Library applications, such as isql, work as SQL Server 6.5–level clients
  when connected to SQL Server 2000. They do not support some SQL Server
  2000 features.
  The osql utility is based on ODBC and does support all SQL Server 2000
  features. Use osql to run scripts that isql cannot run.
162.    What Tool you have used for checking Query Optimization? What
  is the use of profiler in sql server? What is the first thing u look at in a
  SQL Profiler?
  SQL Profiler is a graphical tool that allows system administrators to monitor
  events in an instance of Microsoft® SQL Server™. You can capture and save
  data about each event to a file or SQL Server table to analyze later. For
  example, you can monitor a production environment to see which stored
  procedures is hampering performance by executing too slowly.
  Use SQL Profiler to:
              Monitor the performance of an instance of SQL Server.
              Debug Transact-SQL statements and stored procedures.
              Identify slow-executing queries.
              Test SQL statements and stored procedures in the development
        phase of a project by single-stepping through statements to confirm that
        the code works as expected.
              Troubleshoot problems in SQL Server by capturing events on a
        production system and replaying them on a test system. This is useful
        for testing or debugging purposes and allows users to continue using the
        production system without interference.

  Audit and review activity that occurred on an instance of SQL Server. This
  allows a security administrator to review any of the auditing events, including
  the success and failure of a login attempt and the success and failure of
  permissions in accessing statements and objects.


163.    A user is a member of Public role and Sales role. Public role has
  the permission to select on all the table, and Sales role, which doesn‟t
  have a select permission on some of the tables. Will that user be able
  to select from all tables?
164.    If a user does not have permission on a table, but he has
  permission to a view created on it, will he be able to view the data in
165.    Describe Application Role and explain a scenario when you will
  use it?
166.    After removing a table from database, what other related objects
  have to be dropped explicitly?
  (view, SP)

                                 Page 126 of 165
167.    You have a SP names YourSP and have the a Select Stmt inside
  the SP. You also have a user named YourUser. What permissions you
  will give him for accessing the SP.
168.    Different Authentication modes in Sql server? If a user is logged
  under windows authentication mode, how to find his userid?
  There are Three Different authentication modes in sqlserver.
     0.       Windows Authentication Mode
     1.       SqlServer Authentication Mode
     2.       Mixed Authentication Mode

   ―system_user‖ system function in sqlserver to fetch the logged on user name.

169.    Give the connection strings from front-end for both type
  This are specifically for sqlserver not for any other RDBMS
  Data Source=MySQLServer;Initial Catalog=NORTHWIND;Integrated
  Security=SSPI (windows)
  Data Source=MySQLServer;Initial Catalog=NORTHWIND;Uid=‖ ‖;Pwd=‖
170.    What are three SQL keywords used to change or set someone‟s
  Grant, Deny and Revoke

171.    Explain the architecture of SQL Server?
172.    Different types of Backups?
     o         A full database backup is a full copy of the database.
     o         A transaction log backup copies only the transaction log.
     o         A differential backup copies only the database pages modified after
        the last full database backup.
     o         A file or filegroup restore allows the recovery of just the portion of
        a database that was on the failed disk.
173.    What are „jobs‟ in SQL Server? How do we create one? What is
  Using SQL Server Agent jobs, you can automate administrative tasks and run
  them on a recurring basis.
174.    What is database replication? What are the different types of
  replication you can set up in SQL Server? How are they used? What is
  snapshot replication how is it different from Transactional replication?
  Replication is the process of copying/moving data between databases on the
  same or different servers. SQL Server supports the following types of
  replication scenarios:
     0.        Snapshot replication - It distributes data exactly as it appears at a
        specific moment in time and doesn‘t monitor for updates. It can be used
        when data changes are infrequent. It is often used for browsing data

                                   Page 127 of 165
          such as price lists, online catalog, or data for decision support where the
          current data is not required and data is used as read only.
     1.         Transactional replication (with immediate updating subscribers,
          with queued updating subscribers) - With this an initial snapshot of data
          is applied, and whenever data modifications are made at the publisher,
          the individual transactions are captured and propagated to the
     2.         Merge replication - It is the process of distributing the data
          between publisher and subscriber, it allows the publisher and subscriber
          to update the data while connected or disconnected, and then merging
          the updates between the sites when they are connected.
175.      How can u look at what are the process running on SQL server?
  How     can you kill a process in SQL server?
     o          Expand a server group, and then expand a server.
     o          Expand Management, and then expand Current Activity.
     o          Click Process Info. The current server activity is displayed in the
          details pane.

  In the details pane, right-click a Process ID, and then click Kill Process.

176.     What is RAID and what are different types of RAID
  RAID stands for Redundant Array of Inexpensive Disks, used to provide fault
  tolerance to database servers. There are six RAID levels 0 through 5 offering
  different levels of performance, fault tolerance.
  Some of the tools/ways that help you troubleshooting performance problems
  ON, SQL Server Profiler, Windows NT /2000 Performance monitor, Graphical
  execution plan in Query Analyzer.
178.     How to determine the service pack currently installed on SQL
  The global variable @@Version stores the build number of the sqlservr.exe,
  which is used to determine the service pack installed.
  eg: Microsoft SQL Server 2000 - 8.00.760 (Intel X86) Dec 17 2002 14:22:05
  Copyright (c) 1988-2003 Microsoft Corporation Enterprise Edition on Windows
  NT 5.0 (Build 2195: Service Pack 3)
179.     What is the purpose of using COLLATE in a query?
  The term, collation, refers to a set of rules that determine how data is sorted
  and compared. In Microsoft® SQL Server 2000, it is not required to separately
  specify code page and sort order for character data, and the collation used for
  Unicode data. Instead, specify the collation name and sorting rules to use.
  Character data is sorted using rules that define the correct character
  sequence, with options for specifying case-sensitivity, accent marks, kana
  character types, and character width. Microsoft SQL Server 2000 collations
  include these groupings:
              Windows collations - Windows collations define rules for storing
         character data based on the rules defined for an associated Windows
         locale. The base Windows collation rules specify which alphabet or

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         language is used when dictionary sorting is applied, as well as the code
         page used to store non-Unicode character data. For Windows collations,
         the nchar, nvarchar, and ntext data types have the same sorting
         behavior as char, varchar, and text data types
              SQL collations - SQL collations are provided for compatibility with
         sort orders in earlier versions of Microsoft SQL Server.

  Sort Order
  Binary is the fastest sorting order, and is case-sensitive. If Binary is selected,
  the Case-sensitive, Accent-sensitive, Kana-sensitive, and Width-
  sensitive options are not available.

   Sort order                                  Description
  Binary      Sorts and compares data in Microsoft® SQL Server™ tables based on
              the bit patterns defined for each character. Binary sort order is case-
              sensitive, that is lowercase precedes uppercase, and accent-sensitive.
              This is the fastest sorting order.
              If this option is not selected, SQL Server follows sorting and comparison
              rules as defined in dictionaries for the associated language or alphabet.
  Case-       Specifies that SQL Server distinguish between uppercase and lowercase
  sensitive letters.
              If not selected, SQL Server considers the uppercase and lowercase
              versions of letters to be equal. SQL Server does not define whether
              lowercase letters sort lower or higher in relation to uppercase letters
              when Case-sensitive is not selected.
  Accent-     Specifies that SQL Server distinguish between accented and unaccented
  sensitive characters. For example, 'a' is not equal to 'á'.
              If not selected, SQL Server considers the accented and unaccented
              versions of letters to be equal.
  Kana-       Specifies that SQL Server distinguish between the two types of
  sensitive Japanese kana characters: Hiragana and Katakana.
              If not selected, SQL Server considers Hiragana and Katakana characters
              to be equal.
  Width-      Specifies that SQL Server distinguish between a single-byte character
  sensitive (half-width) and the same character when represented as a double-byte
              character (full-width).
              If not selected, SQL Server considers the single-byte and double-byte
              representation of the same character to be equal.

  Windows collation options:

            Use Latin1_General for the U.S. English character set (code page
            Use Modern_Spanish for all variations of Spanish, which also use
       the same character set as U.S. English (code page 1252).
            Use Arabic for all variations of Arabic, which use the Arabic
       character set (code page 1256).
            Use Japanese_Unicode for the Unicode version of Japanese
       (code page 932), which has a different sort order from Japanese, but
       the same code page (932).
180.   What is the STUFF Function and how does it differ from the
  REPLACE function?
  STUFF - Deletes a specified length of characters and inserts another set of

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  characters at a specified starting point.
  SELECT STUFF('abcdef', 2, 3, 'ijklmn')
  Here is the result set:

  REPLACE - Replaces all occurrences of the second given string expression in
  the first string expression with a third expression.
  SELECT REPLACE('abcdefghicde','cde','xxx')
  Here is the result set:

181.     What does it mean to have quoted_identifier on? What are the
  implications of having it off?
  When SET QUOTED_IDENTIFIER is OFF (default), literal strings in expressions
  can be delimited by single or double quotation marks.
  When SET QUOTED_IDENTIFIER is ON, all strings delimited by double
  quotation marks are interpreted as object identifiers. Therefore, quoted
  identifiers do not have to follow the Transact-SQL rules for identifiers.
  SET QUOTED_IDENTIFIER must be ON when creating or manipulating indexes
  on computed columns or indexed views. If SET QUOTED_IDENTIFIER is OFF,
  CREATE, UPDATE, INSERT, and DELETE statements on tables with indexes on
  computed columns or indexed views will fail.
  The SQL Server ODBC driver and Microsoft OLE DB Provider for SQL Server
  automatically set QUOTED_IDENTIFIER to ON when connecting.
  When a stored procedure is created, the SET QUOTED_IDENTIFIER and SET
  ANSI_NULLS settings are captured and used for subsequent invocations of that
  stored procedure. When executed inside a stored procedure, the setting of SET
  QUOTED_IDENTIFIER is not changed.
  -- Attempt to create a table with a reserved keyword as a name
  -- should fail.
  CREATE TABLE "select" ("identity" int IDENTITY, "order" int)

  -- Will succeed.
  CREATE TABLE "select" ("identity" int IDENTITY, "order" int)
182.     What is the purpose of UPDATE STATISTICS?
  Updates information about the distribution of key values for one or more
  statistics groups (collections) in the specified table or indexed view.
183.     Fundamentals of Data warehousing & olap?
184.     What do u mean by OLAP server? What is the difference between
  OLAP and OLTP?

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185.    What is a tuple?
  A tuple is an instance of data within a relational database.
186.    Services and user Accounts maintenance
187.    sp_configure commands?
  Displays or changes global configuration settings for the current server.
188.    What is the basic functions for master, msdb, tempdb databases?
  Microsoft® SQL Server 2000 systems have four system databases:
              master - The master database records all of the system level
        information for a SQL Server system. It records all login accounts and all
        system configuration settings. master is the database that records the
        existence of all other databases, including the location of the database
              tempdb - tempdb holds all temporary tables and temporary
        stored procedures. It also fills any other temporary storage needs such
        as work tables generated by SQL Server. tempdb is re-created every
        time SQL Server is started so the system starts with a clean copy of the
        By default, tempdb autogrows as needed while SQL Server is running. If
        the size defined for tempdb is small, part of your system processing
        load may be taken up with autogrowing tempdb to the size needed to
        support your workload each time to restart SQL Server. You can avoid
        this overhead by using ALTER DATABASE to increase the size of
              model - The model database is used as the template for all
        databases created on a system. When a CREATE DATABASE statement is
        issued, the first part of the database is created by copying in the
        contents of the model database, then the remainder of the new
        database is filled with empty pages. Because tempdb is created every
        time SQL Server is started, the model database must always exist on a
        SQL Server system.
              msdb - The msdb database is used by SQL Server Agent for
        scheduling alerts and jobs, and recording operators.
189.    What are sequence diagrams? What you will get out of this
  sequence diagrams?
  Sequence diagrams document the interactions between classes to achieve a
  result, such as a use case. Because UML is designed for object-oriented
  programming, these communications between classes are known as messages.
  The sequence diagram lists objects horizontally, and time vertically, and
  models these messages over time.
190.    What are the new features of SQL 2000 than SQL 7? What are the
  new datatypes in sql?
              XML Support - The relational database engine can return data as
        Extensible Markup Language (XML) documents. Additionally, XML can
        also be used to insert, update, and delete values in the database. (for
        xml raw - to retrieve output as xml type)
              User-Defined Functions - The programmability of Transact-SQL can
        be extended by creating your own Transact-SQL functions. A user-
        defined function can return either a scalar value or a table.

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              Indexed Views - Indexed views can significantly improve the
        performance of an application where queries frequently perform certain
        joins or aggregations. An indexed view allows indexes to be created on
        views, where the result set of the view is stored and indexed in the
              New Data Types - SQL Server 2000 introduces three new data
        types. bigint is an 8-byte integer type. sql_variant is a type that
        allows the storage of data values of different data types. table is a type
        that allows applications to store results temporarily for later use. It is
        supported for variables, and as the return type for user-defined
              INSTEAD OF and AFTER Triggers - INSTEAD OF triggers are
        executed instead of the triggering action (for example, INSERT, UPDATE,
        DELETE). They can also be defined on views, in which case they greatly
        extend the types of updates a view can support. AFTER triggers fire after
        the triggering action. SQL Server 2000 introduces the ability to specify
        which AFTER triggers fire first and last.
              Multiple Instances of SQL Server - SQL Server 2000 supports
        running multiple instances of the relational database engine on the same
        computer. Each computer can run one instance of the relational
        database engine from SQL Server version 6.5 or 7.0, along with one or
        more instances of the database engine from SQL Server 2000. Each
        instance has its own set of system and user databases.
              Index Enhancements - You can now create indexes on computed
        columns. You can specify whether indexes are built in ascending or
        descending order, and if the database engine should use parallel
        scanning and sorting during index creation.
191.    How do we open SQL Server in single user mode?
  We can accomplish this in any of the three ways given below :-
      .        From Command Prompt :-
        sqlservr -m
     a.        From Startup Options :-
        Go to SQL Server Properties by right-clicking on the Server name in the
        Enterprise manager.
        Under the 'General' tab, click on 'Startup Parameters'.
        Enter a value of -m in the Parameter.
     b.        From Registry :-
        Go to
        Add new string value.
        Specify the 'Name' as SQLArg(n) & 'Data' as -m.
        Where n is the argument number in the list of arguments.
192.    Difference between clustering and NLB (Network Load
193.    Explain Active/Active and Active/Passive cluster configurations?

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194.    What is Log Shipping?
  In Microsoft® SQL Server™ 2000 Enterprise Edition, you can use log shipping
  to feed transaction logs from one database to another on a constant basis.
  Continually backing up the transaction logs from a source database and then
  copying and restoring the logs to a destination database keeps the destination
  database synchronized with the source database. This allows you to have a
  backup server and also provides a way to offload query processing from the
  main computer (the source server) to read-only destination servers.
195.    What are the main steps you take care for enhancing SQL Server
196.    You have to check whether any users are connected to sql server
  database and if any user is connected to database, you have to
  disconnect the user(s) and run a process in a job. How do you do the
  above in a job?

197.    How can I convert data in a Microsoft Access table into XML
  The following applications can help you convert Access data into XML format:
  Access 2002, ADO 2.5, and SQLXML. Access 2002 (part of Microsoft Office XP)
  enables you to query or save a table in XML format. You might be able to
  automate this process. ADO 2.5 and later enables you to open the data into a
  recordset, then persist the recordset in XML format, as the following code
  rs.Save "c:\rs.xml", adPersistXML
  You can use linked servers to add the Access database to your SQL Server
  2000 database so you can run queries from within SQL Server to retrieve data.
  Then, through HTTP, you can use the SQLXML technology to extract the Access
  data in the XML format you want.

198.    @@IDENTITY ?
  Ans: Returns the last-inserted identity value.
199.    If a job is fail in sql server, how do find what went wrong?
200.    Have you used Error handling in DTS?

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                           Microsoft .NET Glossary
                               By Staff


Access modifiers—Language keywords used to specify the visibility of the methods
and member variables declared within a class. The five access modifiers in the C#
language are public, private, protected, internal, and protected internal.

Active Server Pages (ASP)—A Microsoft technology for creating server-side, Web-
based application services. ASP applications are typically written using a scripting
language, such as JScipt, VBScript, or PerlScript. ASP first appeared as part of
Internet Information Server 2.0 and was code-named Denali.

ADO (ActiveX Data Objects)—A set of COM components used to access data objects
through an OLEDB provider. ADO is commonly used to manipulate data in databases,
such as Microsoft SQL Server 2000, Oracle, and Microsoft Access.

ADO.NET (ActiveX Data Objects for .NET)—The set of .NET classes and data
providers used to manipulate databases, such as Microsoft SQL Server
2000. ADO.NET was formerly known as ADO+. ADO.NET can be used by any .NET

Aero—The code name for the user experience provided by Microsoft's Longhorn
Operating System.

API (Application Program Interface)—A set of programs, code libraries, or
interfaces used by developers to interact with a hardware device, network, operating
system, software library, or application. Calls to the methods of an API are typically
synchronous, but may also be asynchronous through the use of callback methods.

Application assembly cache—See Local assembly cache.

Application base—The directory where a .NET application's assembly files are
stored. Also called the application folder or application directory.

Application Center 2000—A deployment and management package for Web sites,
Web services, and COM components. Application Center is a key B2B and B2C
component of the .NET Enterprise Server product family.

Application domain—The logical and physical boundary created around every .NET
application by the CLR. The CLR can allow multiple .NET applications to be run in a
single process by loading them into separate application domains. The CLR isolates
each application domain from all other application domains and prevents the
configuration, security, or stability of a running .NET applications from affecting
other applications. Objects can only be moved between application domains by the
use of remoting.

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Application Manifest—The part of an application that provides information to
describe the components that the application uses.

Array—A collection of objects of the same type, all of which are referenced by a
single identifier and an indexer. In the .NET Framework, all arrays inherits from the
Array class that is located in the System namespace.

ASP.NET (Active Server Pages for .NET)—A set of .NET classes used to create Web-
based, client-side (Web Form) and server-side (Web Service) applications. ASP.NET
was derived from the Microsoft Active Server Pages (ASP) Web technology and
adapted for use in the .NET Framework. Also called managed ASP and formerly
known as ASP+.

Assembly—All of the files that comprise a .NET application, including the resource,
security management, versioning, sharing, deployment information, and the actual
MSIL code executed by the CLR. An assembly may appear as a single DLL or EXE
file, or as multiple files, and is roughly the equivalent of a COM module. See
assembly manifest, private assembly, shared assembly.

Assembly Binding Log Viewer—A .NET programming tool (Fuslogvw.exe) used to
view and manipulate the log of binding information that is updated at run-time when
an assembly is loaded by the CLR. This log viewer is primarily used to discover why
an assembly (or satellite assembly) can't be located at runtime, and to verify that
the correct assemblies are being loaded by a .NET application.

Assembly cache—A reserved area of memory used to store the assemblies of a
.NET applications running on a specific machine. See Global Assembly Cache, Local
assembly cache, Download Cache.

Assembly Cache Viewer—A .NET programming tool (Shfusion.dll) used to view,
add, remove and configure information in the Global Assembly Cache using Windows
Explorer. This viewer is used by clicking on the %WINDIR\Assembly folder in
Windows Explorer. See Global Assembly Cache Utility.

Assembly Dependency List—A .NET programming tool (ADepends.exe) used to
display all of the assemblies that a specific assembly is dependent upon.

Assembly informational version—A custom attribute that attaches version
information to an assembly in addition to the assembly's version number. The
informational version is a string that typically contains marketing information, such
as the product's name and release number (e.g., "Windows 2000 Server" or
"FantastiWidget 3.0").

Assembly Linking Utility—A .NET programming tool (al.exe) used to create an
assembly manifest from the specified MSIL modules or resource files. Also call the
Assembly Linker and Assembly Generation Utility.

Assembly manifest—A detailed description of the contents of an assembly. A
manifest contains metadata describing the name, version, types, and resources in

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the assembly, and the dependencies upon other assemblies. The manifest allows an
assembly to be self-describing, easily deployed, and not bound to a particular
system by storing information in the Windows registry.

Assembly metadata—The metadata stored in assembly files.

Assembly Registration Tool—A .NET programming tool (RegAsm.exe) used to
register an assembly in the Windows registry. Registration is required if COM clients
need to call managed methods residing in a .NET assembly. This tool can also be
used to generate a registry (.reg) file containing the necessary registration
information. Registration typically only occurs once when the assembly is installed.

Assembly version number—Part of an assembly's identity, and used to indicate
the version, revision, and build of an assembly. The version is expressed in dot
notation using four, 32-bit integers in the format "<major version>.<minor
version>.<build number>.<revision>". The version number is stored in the
assembly manifest and only refers to the contents of a single assembly Two
assemblies that have version numbers which differ in any way are considered by the
CLR to be completely different assemblies. See Assembly informational version.

Attribute-based programming—A programming model that allows flexibility in the
behavior of a program not possible in traditional API call-based programming.
Custom attributes add metadata to give classes extra information that extend the
definition a types' behavior. The attribute's values are determined by programmers
at design time, and can be reconfigured at runtime by users and other programs
without the need for code changes or recompilation. See Reflection.

Attributes—Language constructs that are used by programmers to add additional
information (i.e., metadata) to code elements (e.g., assemblies, modules, members,
types, return values, and parameters) to extend their functionality. See Custom

Avalon—The code name for for the graphical subsystem (User Interface framework)
of Longhorn. It is worth noting that this will be a vector-based system.


B2B—Business-to-Business. The exchange of information between business entities.

B2C—Business-to-Consumer. The exchange of information between business and
consumer (i.e., customer) entities.

BackOffice Server 2000—A suite of Microsoft servers applications used for B2B
and B2C services. Included in this suite are Windows 2000 Server, Exchange Server
2000, SQL Server 2000, Internet Security and Acceleration Server 2000, Host
Integration Server 2000, and Systems Management Server 2.0. These server

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applications are now referred to as the .NET Enterprise Server product family.

Base class—The parent class of a derived class. Classes may be used to create
other classes. A class that is used to create (or derive) another class is called the
base class or super class. See Derived Class, Inheritance.

BizTalk Server 2000—A set of Microsoft Server applications that allow the
integration, automation, and management of different applications and data within
and between business organizations. BizTalk Server is a key B2B component of the
.NET Enterprise Server product family.

Boxing—Conversion of a value type to a reference type object (i.e. System.Object).
Value types are stored in stack memory and must be converted (i.e., boxed) to a
new object in heap memory before they can be manipulated as objects. The
methods, functions, and events of the new object are invoked to perform operations
on the value (e.g., converting an integer to a string). Boxing is implicitly performed
by the CLR at runtime. See Unboxing.

Built-in Types—See Pre-defined types.

Burton—The codename for Microsoft Visual Studio 2005 Team System.


C# (C-Sharp)—An object-oriented and type-safe programming language supported
by Microsoft for use with the .NET Framework. C# (pronounced "see-sharp") was
created specifically for building enterprise-scale applications using the .NET
Framework. It is similar in syntax to both C++ and Java and is considered by
Microsoft as the natural evolution of the C and C++ languages. C# was created by
Anders Hejlsberg (author of Turbo Pascal and architect of Delphi), Scot Wiltamuth,
and Peter Golde. C# is defined by the standard ECMA-334.

Callback Method—A method used to return the results of an asynchronous
processing call. Typically, methods are called in a synchronous fashion, where the
call does not return until the results (i.e., the output or return value) of the call are
available. An asynchronous method call returns prior to the results, and then
sometime later a callback method is called to return the actual results. The callback
method itself contains program statements that are executed in response to the
reception of the results. Also referred to as a callback function under the Win32 API.
See Event.

Casting—Conversion of a value from one type to another. Implicit casting is
performed silently by the compiler when the casting would not cause any information
to be lost (e.g., converting a 16-bit integer to a 32-bit integer value). Explicit casting
is coded by the programmer using the particular language's cast operator. This is
necessary when the use of a value would cause a possible loss of data (e.g.,
converting a 32-bit integer to a 16-bit integer value).

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Catching—To trap a program exception. See try/catch block.

Class—In .NET languages, classes are templates used for defining new types.
Classes describe both the properties and behaviors of objects. Properties contain the
data that are exposed by the class. Behaviors are the functionality of the object, and
are defined by the public methods (also called member functions) and events of the
class. Collectively, the public properties and methods of a class are known as the
object interface. Classes themselves are not objects, but instead they are used to
instantiate (i.e., create) objects in memory. See structure.

Class members—The elements of a class which define it behaviors and properties.
Class members include events, member variables, methods, constructors, and
properties. Also called type members.

ClickOnce—A deployment technology introduced with the release of Whidbey that
allows client program to be used and installed as seamless as Web applications. This
includes the ability to download files to be installed, versioning, side-by-side
installation, and more.

Client—Any application that requests information or services from a server. See
Client/Server architecture.

Client-side—An operation or event that occurs on a client system. Examples include
client-side scripting, client-side validation, and client-side events. See Server-side.

Client/Server architecture—An application architecture in which the server
dispenses (or serves) information that is requested by one or more client
applications. In the 2-tier client/server model, the client contain the user interface
and business logic, and the server contains the database engine and information
storage. In the 3-tier model, the business logic is located on a middle-tier server to
reduce the processing load on the database server and to make system maintenance
easier. The number of users that can be supported by a client/server system is
based on the bandwidth and load of the network and processing power of the server.
See Distributed architecture.

CLR Debugger—A .NET programming tool (DbgClr.exe) used as a Windows-based,
source-level debugging utility for MSIL applications. See Runtime Debugger.

CLR Minidump Tool—A .NET programming tool (Mscordmp.exe) used to produce a
mini-dump image file (i.e., a core dump) of the CLR at runtime. This tool is used to
examine runtime problems by taking a snapshot of the CLR as the problems occurs.
Windows automatically invokes the CLR Minidump Tool prior to running the Dr.
Watson utility (Drwatson.exe).

Code Access Security (CAS)—The common language runtime's security model for
applications. This is the core security model for new features of the Longhorn
Operating System.

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Collection—A class used to logically organize a group of identical types using a
single identifier. Examples of collection types in the .NET Framework include array,
arraylist, queue, and stack.

COM (Component Object Model)—A software architecture developed by Microsoft to
build component-based applications. COM objects are discrete components, each
with a unique identity, which expose interfaces that allow applications and other
components to access their features. COM objects are more versatile that Win32
DLLs because they are completely language independent, have built-in interprocess
communications capability, and easily fit into an Object-Oriented program design.
COM was first released in 1993 with OLE2, largely to replace the interprocess
communication mechanism Dynamic Data Exchanged (DDE) used by the initial
release of OLE. See COM+.

COM+—The "next generation" of the COM and DCOM software architectures. COM+
(pronounced "COM plus") makes it easier to design and construct distributed,
transactional, and component-based applications using a multi-tiered architecture.
COM+ also supports the use of many new services, such as Just-in-Time Activation,
object pooling, and Microsoft Transaction Server (MTS) 2.0. The use of COM, DCOM,
and COM+ in application design will eventually be entirely replaced by the Microsoft
.NET Framework.

COM+ 2.0—This was one of the pre-release names for the original Microsoft .NET
Framework. See also Web Services Platform.

COM Callable Wrapper (CCW)—A metadata wrapper that allows COM components
to access managed .NET objects. The CCW is generated at runtime when a COM
client loads a .NET object. The .NET assembly must first be registered using the
Assembly Registration Tool. See Runtime Callable Wrapper (RCW).

Commerce Server 2000—Microsoft's e-commerce server application package for
developing and maintaining business Web sites. Commerce Server is a key
component to creating B2C solutions using the .NET Enterprise Server product

Common Intermediate Language (CIL)—The system-independent code generated
by a .NET language compiler. CIL defines a file format for storing managed code as
both program instructions and metadata in a single file. Either the ILASM assembler
or JIT compiler is then used to convert CIL to native machine code. CIL is also
referred to as Microsoft Intermediate Language (MSIL).

Common Language Infrastructure (CLI)—The .NET infrastructure that allows
applications written in multiple programming languages to operate many different
environments without the need to modify the program code. The CLI consists of a
file format (PE), a common type system (CTS), an extensible metadata system, an
intermediate language (CIL), a factored base class library (FCL), and access to the

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underlying operating system (Win32). The CLI is defined by the standard ECMA-335.

Common Language Runtime (CLR)—A runtime environment that manages the
execution of .NET program code, and provides services such as memory and
exception management, debugging and profiling, and security. The CLR is a major
component of the .NET Framework, and provides much of its functionality by
following the rules defined in the Common Type System. Also known as the Virtual
Execution System (VES).

Common Language Specification (CLS)—A set of common conventions used to
promote interoperability between programming languages and the .NET Framework.
The CLS specifies a subset of the Common Type System and set of conventions that
are adhered to by both programming language designers and framework class
library authors.

Common Object File Format (COFF)—See Portable Executable file.

Common Type System (CTS)—The .NET Framework specification which defines the
rules of how the Common Language Runtime defines, declares, and manages types,
regardless of the programming language. All .NET components must comply to the
CTS specification.

Content Management Server 2001—Microsoft's server package for building,
deploying, and maintaining dynamic content for both private or commercial Web

Constructor—A method that is automatically called when an object is created. The
constructor is used to initialize the object and place it in a valid state (e.g., setting
the values of member variables). The constructor method always has the same
identifier as the class in which it is defined. See Destructor.

Cool—The pre-release code name used for C#.

CSC—The .NET C# command line compiler (csc.exe).

Custom Attributes—Attributes defined by a programmer to store the instance of
any type in metadata. See Attribute-based programming, Reflection.


Data provider—A set of classes in the .NET Framework that allow access to the
information a data source. The data may be located in a file, in the Windows
registry, or any any type of database server or network resource. A .NET data
provider also allows information in a data source to be accessed as an ADO.NET
DataSet. Programmers may also author their own data providers for use with the
.NET Framework. See Managed providers.

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DCOM (Distributed Component Object Model)—An extension of the Microsoft
Component Object Model (COM) that allows COM components to communicate
across network boundaries. Traditional COM components can only perform
interprocess communication across process boundaries on the same machine. DCOM
uses the Remote Procedure Call (RPC) mechanism to transparently send and receive
information between COM components (i.e., clients and servers) on the same
network. DCOM was first made available in 1995 with the initial release of Windows
NT 4.

Delegate—A mechanism used to implement event handling in .NET Framework
code. A class that needs to raise events must define one delegate per event. Types
that use the class must implement one event handler method per event that must be
processed. Delegates are often described as a managed version of a C++ function
pointer. However, delegates can reference both instance and static (also called
shared) methods, while function pointers can only reference static methods.

Deployment—The process of installing an application, service, or content on to one
or more computer systems. In .NET, deployment is performed using XCOPY or the
Windows Installer. More complex deployment applications, such as System
Management Server, can also be used. See Installer Tool.

Deployment Manifest—The part of an application that tells the system how to
install and maintain an application.

Derived class—A class that was created based on a previously existing class (i.e.,
base class). A derived class inherits all of the member variables and methods of the
base class it is derived from. Also called a derived type.

Destructor—In traditional Object Oriented Programming, a destructor is a class
method that is called when an object goes out of scope. In .NET languages, the
destructor method is instead called when the object is garbage collected by the
CLR—which happens at some indeterminate time after an object goes out of scope.
In C#, the destructor is actually a syntactic mapping to a Finalize method. See
Constructor, Dispose.

DOM (Document Object Model)—A programming interface that allows HTML pages
and XML documents to be created and modified as if they were program objects.
DOM makes the elements of these documents available to a program as data
structures, and supplies methods that may be invoked to perform common
operations upon the document's structure and data. DOM is both platform- and
language-neutral and is a standard of the World Wide Web Consortium (W3C).

DISCO—An Microsoft-created XML protocol used for discovering Web Services. Much
of DISCO is now a subset in the newer, more universal protocol UDDI. It is expected
that DISCO will become obsolete in favor of UDDI.

Dispose—A class-only method used to implement an explicit way to release the
resources allocated by an object. The dispose method is actually in implementation of
the IDisposable interface, and is typically called by the destructor or Finialize method of

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a class.

Distributed architecture—An application architecture in which the components of
an application may be distributed across many computers. Although the client/server
architecture is fundamentally distributed in its design, the distributed model is not
limited to only two or three tiers in its design. A distributed, n-tier architecture may
use many components running on dozens, hundreds or thousands of computers on a
network to service a single application. This concept is reflected in Sun
Microsystems' visionary phrase, "The network is the computerTM."

Download Cache—Part of the assembly cache used to store information
downloaded from a private network or the public Internet. Objects in the download
cache are effectively isolated from all other assemblies loaded into other assembly
caches. See Assembly Cache.

DSI—Microsoft's Distributed System Initiative.

DTD (Document Type Definition)—A document defining the format of the contents
present between the tags in an HTML, XML, or SGML document, and how the content
should be interpreted by the application reading the document. Applications will use
a document's DTD to properly read and display a document's contents. Changes in
the format of the document can be easily made by modifying the DTD.


ECMA (European Computer Manufactures Association)—The ECMA (known since
1994 as ECMA International) is an industry association founded in 1961 and
dedicated to the standardization of information and communication systems. The C#
and CLI specification were ratified by the ECMA on December 31, 2001 as
international standards, and assigned to them the ECMA standards designations of
ECMA-334 (C#) and ECMA-335 (CLI), and Technical Report TR-84. These standards
are available at

Enterprise Instrumentation Framework (EIF)—A feature that expands the
program execution tracing capabilities found in the initial release of the .NET
Framework. EIF allows the use of configurable event filtering and tracing by
integrating .NET applications with the event log and tracing services built into the
Windows operating system. Warnings, errors, business events, and diagnostic
information can be monitored and reported for immediate, runtime analysis by
developers, or collected and stored for later use by technical support personnel.
Support for EIF will be included in the next release of Visual Studio.NET.

Event—A notification by a program or operating system that "something has
happened." An event may be fired (or raised) in response to the occurrence of a pre-
defined action (e.g., a window getting focus, a user clicking a button, a timer
indicating a specific interval of time has passed, or a program starting up or shutting
down). In response to an event, an event handler is called.

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Event Handler—A function or method containing program statements that are
executed in response to an event. See Callback method.

Everett—The pre-release code name of Visual Studio .NET 2003. Everett offers
increased performance over Visual Studio .NET 1.0, integration with Windows Server
2003 and SQL Server 2003 (Yukon), extended support for XML Web services, MS
Office programmability (the Visual Studio Tools for Office Development), improved
migration tools for VB6 code, new managed data providers for Oracle and ODBC, and
the addition of the Enterprise Instrumentation Framework (EIF) and mobile device
support in the form of the .NET Compact Framework.

Exception—A signal that is generated when an unplanned or unexpected event
occurs. Exceptions are typically caught by an exception handler and dealt with in an
appropriate way. A fatal exception (also called a critical or catastrophic error) is an
event that cannot be properly handled to allow the application—or the operating
system—to continue running.

Exception Handling—The process of trapping an exception and performing some
sort of corrective procedure in response. See try/catch block.

Exchange Server 2000—A set of Microsoft server applications use to ingrate
messaging and data storage technologies. Exchange Server's features include instant
messaging, email, calendaring, real-time conferencing, and contact management.
Exchange Server can also store documents, Web content, and applications that are
accessible via Internet protocols, such as NNTP and HTTP.

Executable file—A file containing program instructions that are executed by an
operating system or runtime environment. See Portable Executable file.

Extensible Markup Language (XML)—See XML.


Fields—Same as member variables.

Finalize—A class-only method that is automatically called when an object is
destroyed by the garbage collector. The Finalize method is primarily used to free up
unmanaged resources allocated by the object before the object itself is removed
from memory. A Finalize method is not needed when only managed resources are
used by the object, which are automatically freed by the garbage collector. In C#,
when a destructor is defined in a class it is mapped to a Finalize method. Also called a
finalizer. See Dispose.

Finally block—A block of program statements that will be executed regardless if an
exception is thrown or not. A finally block is typically associated with a try/catch

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block (although a catch block need not be present to use a finally block). This is
useful for operations that must be performed regardless if an exception was thrown
or not (e.g., closing a file, writing to a database, deallocating unmanaged memory,

Framework Class Library (FCL)—The collective name for the thousands of classes
that compose the .NET Framework. The services provided by the FCL include runtime
core functionality (basic types and collections, file and network I/O, accessing
system services, etc.), interaction with databases, consuming and producing XML,
and support for building Web-based (Web Form) and desktop-based (Windows Form)
client applications, and SOAP-based XML Web services.


Garbage Collection (GC)—The process of implicitly reclaiming unused memory by
the CLR. Stack values are collected when the stack frame they are declared within
ends (e.g., when a method returns). Heap objects are collected sometime after the
final reference to them is destroyed.

GDI (Graphics Device Interface)—A Win32 API that provides Windows applications
the ability to access graphical device drivers for displaying 2D graphics and
formatted text on both the video and printer output devices. GDI (pronounced "gee
dee eye") is found on all version of Windows. See GDI+.

GDI+ (Graphics Device Interface Plus)—The next generation graphics subsystem
for Windows. GDI+ (pronounced "gee dee eye plus") provides a set of APIs for
rendering 2D graphics, images, and text, and adds new features and an improved
programming model not found in its predecessor GDI. GDI+ is found natively in
Windows XP and the Windows Server 2003 family, and as a separate installation for
Windows 2000, NT, 98, and ME. GDI+ is the currently the only drawing API used by
the .NET Framework.

Global Assembly Cache (GAC)—A reserved area of memory used to store the
assemblies of all of the .NET applications running on a specific machine. The GAC is
necessary for side-by-side execution and for the sharing of assemblies among
multiple applications. To reside in the GAC, an assembly must be public (i.e., a
shared assembly) and have a strong name. Assemblies are added and removed from
the GAC using the Global Assembly Cache Tool.

Global Assembly Cache Tool—A .NET programming tool (GACUtil.exe) used to
install, uninstall, and list the contents of the Global Assembly Cache. This tool is
similar in function to the Assembly Cache Viewer that run on Windows Explorer, but
as a separate program it can be called from batch files, makefiles, and scripts.

Globalization—The practice of designing and developing software that can be
adapted to run in multiple locales. Globalized software does not make assumptions
about human language, country, regional, or cultural information based on a single

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locale. Instead, the software is written to change the locale-specific information it
uses to process data and display information to the user based on the configured
locale of the operating system, or the personal preference of the user. Also called
internationalization. See localization, satellite assembly.


Hash Code—A unique number generated to identify each module in an assembly.
The hash is used to insure that only the proper version of a module is loaded at
runtime. The hash number is based on the actual code in the module itself.

Heap—An area of memory reserved for use by the CLR for a running programming.
In .NET languages, reference types are allocated on the heap. See Stack.

Host Integration Server 2000—A set of Microsoft server applications use to
ingrate the .NET platform and applications with non-Microsoft operating systems and
hardware (e.g., Unix and AS/400), security systems (e.g., ACF/2 and RACF), data
stores (e.g., DB2), and transaction environments (e.g., CICS and IMS).

HTML (HyperText Markup Language)—A document-layout and hyperlink-
specification language. HTML is used to describe how the contents of a document
(e.g., text, images, and graphics) should be displayed on a video monitor or a
printed page. HTML also enables a document to become interactive with other
documents and resources by using hypertext links embedded into its content. HTML
is the standard content display language of the World Wide Web (WWW), and is
typically conveyed between network hosts using the HTTP protocol. See XHTML.

HTTP (Hyper Text Transfer Protocol)—An Internet protocol used to transport
content and control information across the World Wide Web (WWW). Web content
typically originates from Web servers (also called HTTP servers) that run services
which support the HTTP protocol. Web clients (i.e., Web browsers) access the
content on the server using the rules of the HTTP protocol. The actual Web content is
encoded using the HTML or XHTML languages.


Identifiers—The names that programmers choose for namespaces, types, type
members, and variables. In C# and VB.NET, identifiers must begin with a letter or
underscore and cannot be the same name as a reserved keyword. Microsoft no
longer recommends the use of Hungarian Notation (e.g., strMyString, nMyInteger) or
delimiting underscores (e.g., Temp_Count) when naming identifiers. See Qualified

ILASM—See MSIL Assembler.

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ILDASM—See MSIL Disassembler.

Indigo —The code name for the communications portion of Longhorn that is built
around Web services. This communications technology focuses on providing
spanning transports, security, messaging patterns, encoding, networking and
hosting, and more.

Interface Definition Language (IDL)—A language used to describe object
interfaces by their names, methods, parameters, events, and return types. A
compiler uses the IDL information to generate code to pass data between machines.
Microsoft's IDL, called COM IDL, is compiled using the Microsoft IDL compiler (MIDL).
MIDL generates both type libraries and proxy and stub code for marshaling
parameters between COM interfaces.

Indexer—A CLR language feature that allows array-like access to the properties of
an object using getter and setter methods and an index value. This construct is
identical to operator[] in C++. See Property.

Installer Tool—A .NET programming tool (InstallUtil.exe) used to install or uninstall
one or more assemblies by executing the installer components contained within an
assembly. During installation, all necessary files are saved to the application base
folder and the required resources are created, including the uninstallation

Interface—The set of properties, methods, indexers, and events exposed by an
object that allow other objects to access its data and functionality. An object
guarantees that it will support all of the elements of its interface by way of an
interface contract.

Interface contract—The guarantee by an object that it will support all of the
elements of its interface. In C#, this contract is created by the use of the Interface
keyword, which declares a reference type that encapsulates the contract.

Intermediate Language (IL)—See MSIL.

Inheritance—The ability of a class to be created from another class. The new class,
called a derived class or subclass, is an exact copy of the base class or superclass
and may extend the functionality of the base class by both adding additional types
and methods and overriding existing ones.

Instant fields—The member variables in an object instance.

Internet Security and Acceleration Server 2000—A set of applications used to
provide firewall security and Web caching services to a single Web site or to an
enterprise-scale Web farm.

Intrinsic Types—See Built-in Types.

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Isolated storage—A data storage mechanism used by the CLR to insure isolation
and type safety by defining standardized ways of associating code with saved data.
Data contained in isolated storage is always identified by user and by assembly,
rather than by an address in memory, or the name and path of a file on disk. Other
forms of security credentials, such as the application domain, can also be used to
identify the isolated data.

Isolated storage tool—A .NET programming tool (Storeadm.exe) used to list and
remove all existing stores for the current user. See Isolated storage.


J# (J-Sharp). A Microsoft-supported language for .NET. J# (pronounced "jay sharp")
is Microsoft's implementation of the Java programming language. It specifically
designed to allow Java-language developers to easily transition to the .NET
Framework and to create .NET applications. Tools are also available that allow
existing Java and Microsoft J++ code to be migrated to J#. Because J# compiles to
MSIL and not Java bytecodes, J# applications are not compatible with the Java
Virtual Machine (JVM) or the Java 2 platform. However, J# applications can be
written using Visual Studio .NET and then compiled using third-party Java tools. See
Java Language Conversion Assistant.

J2EE (Java 2 Enterprise Edition)—A Java-based, runtime platform created by Sun
Microsystems used for developing, deploying, and managing multi-tier server-centric
applications on an enterprise-wide scale. J2EE builds on the features of J2SE and
adds distributed communication, threading control, scalable architecture, and
transaction management. J2EE is a competitor to the Microsoft .NET Framework.

J2ME (Java 2 Micro Edition)—A Java-based, runtime platform created by Sun
Microsystems that allows Java applications to run on embedded devices, such as
cellular telephones and Personal Digital Assistants (PDA). J2ME is a competitor to the
Microsoft .NET Compact Framework.

J2SE (Java 2 Standard Edition)—A Java-based, runtime platform that provides
many features for developing Web-based Java applications, including database
access (JDBC API), CORBA interface technology, and security for both local network
and Internet use. J2SE is the core Java technology platform and is a competitor to
the Microsoft .NET Framework.

Java—A computing platform and programming language released by Sun
Microsystems in 1995. A Java application has the ability to run on many different
types of computers, devices, operating systems (e.g., Windows, Macintosh, Linux
and UNIX), and application environments (e.g., Web browsers) without requiring any
changes to its code (this technology is referred to by Sun as "Write Once, Run
AnywhereTM" portability). The Java 2 platform and language is a competitor to the
Microsoft .NET Framework and the J# language. See the java.sun.comWebsite.

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Java Language Conversion Assistant (JLCA)—A tool used to convert Java-
language source code into C# or J# code. JLCA aides in the migration of Java 2
applications to the Microsoft .NET Framework, and is one of the .NET Framework
Migration Tools created by ArtinSoft for Microsoft.

Java Virtual Machine (JVM)—A component of the Java runtime environment that
JIT—compiles Java bytecodes, manages memory, schedules threads, and interacts
with the host operating environment (e.g., a Web browser running the Java
program). The JVM is the Java equivalent of the .NET Framework's CLR.

JScript .NET—A Microsoft-supported language for .NET. JScript .NET (pronounced
"jay script dot net") is Microsoft's "next generation" implementation of the JavaScript
programming language. JScript .NET includes all of the features found in the JScript
language, but also provides support for true object-oriented scripting using classes
and types, and adds features, such as true compiled code, packages, cross-language
support, and access to the .NET Framework.

Just In Time (JIT)—The concept of only compiling units of code just as they are
needed at runtime. The JIT compiler in the CLR compiles MSIL instructions to native
machine code as a .NET application is executed. The compilation occurs as each
method is called; the JIT-compiled code is cached in memory and is never
recompiled more than once during the program's execution.


Keywords—Names that have been reserved for special use in a programming
language. The C# language defines about 80 keywords, such as bool, namespace, class,
static, and while. The 160 or so keywords reserved in VB.NET include Boolean, Event,
Function, Public, and WithEvents. Keywords may not be used as identifiers in program


License Compiler—A .NET programming tool (lc.exe) used to produce .licenses files
that can be embedded in a CLR executable.

Lifetime—The duration from an objects existence. From the time an object is
instantiated to the time it is destroyed by the garbage collector.

Local assembly cache—The assembly cache that stores the compiled classes and
methods specific to an application. Each application directory contains a \bin
subdirectory which stores the files of the local assembly cache. Also call the
application assembly cache. See Global Assembly Cache.

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Local Variable—Same as a member variable.

Locale—A collection of rules and data specific to a spoken and/or written language
and/or a geographic area. Locale information includes human languages, date and
time formats, numeric and monetary conventions, sorting rules, cultural and regional
contexts (semantics), and character classification. See Localization.

Localization—The practice of designing and developing software that will properly
used all of the conventions defined for a specific locale. See Globalization.

Lonestar—The codename for Windows XP Tablet PC Edition 2005.

Longhorn—The "next generation" release of Windows Server after Windows Server

Longhorn API—The application programming interface for the Longhorn operating


Make Utility—A .NET programming tool (nmake.exe) used to interpret script files
(i.e., makefiles) that contain instructions that detail how to build applications,
resolve file dependency information, and access a source code control system.
Microsoft's nmake program has no relation to the nmake program originally created
by AT&T Bell Labs and now maintained by Lucent. Although identical in name and
purpose these two tools are not compatible. See Lucent nmake Web site.

Managed ASP—Same as ASP.NET.

Managed C++—Same as Visual C++ .NET.

Managed code—Code that is executed by the CLR. Managed code provides
information (i.e., metadata) to allow the CLR to locate methods encoded in assembly
modules, store and retrieve security information, handle exceptions, and walk the
program stack. Managed code can access both managed data and unmanaged data.

Managed data—Memory that is allocated and released by the CLR using Garbage
Collection. Managed data can only be accessed by managed code.

Managed execution—The process used by the CLR to execute managed code. Each
time a method in an object is called for the first time, its MSIL-encoded instructions
are JIT-compiled to the native code of the processor. Each subsequent time the
same method is called, the previous JIT-compiled code is executed. Compiling and
execution continued until the program terminates.

Managed Extensions for C++—Language extensions added to the C++ language
that enable developers to write code that makes use of the .NET Framework's CLR.

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See as Visual C++ .NET.

Managed pointer types—An object reference that is managed by the CLR. Used to
point to unmanaged data, such as COM objects and some parameters of Win32 API

Managed pointers—A pointer that directly references the memory of a managed
object. Managed pointers may point to the field of an object or value type, an
element of an array, or the address where the next element just past the end of an
array would be stored.

Managed providers—.NET objects that provide managed access to services using a
simplified data access architecture. The functionality of a provider is accessed via
one or more object interfaces. The most common examples of managed providers
are the data providers, such as SQL Server Managed Provider (System.Data.SqlClient),
OLE DB .NET Data Provider (System.Data.Odbc), and ADO Managed (System.Data.ADO).
.NET managed providers operate completely within the bounds of the CLR and
require no interaction with COM interfaces, the Win32 API, or other unmanaged

Managed resources—A resource that is part of an assembly.

Manifest—See Assembly manifest.

Marshaling—The process of preparing an object to be moved across a context,
process, or application domain boundary. See Remoting.

Members—See Class members.

Member variables—Typed memory locations used to store values. Also called

Metadata—All information used by the CLR to describe and reference types and
assemblies. Metadata is independent of any programming language, and is an
interchange medium for program information between tools (e.g., compilers and
debuggers) and execution environments. See MSIL.

Method—A function defined within a class. Methods (along with events) defined the
behavior of an object.

MIDL (Microsoft Interface Definition Language) Compiler—The program used to
compile Interface Definition Language (IDL) files into type libraries.

Mobile Information Server 2002—A set of applications used for extending
Microsoft .NET applications, enterprise data, and intranet content to mobile client
devices such as cell phones and Personal Digital Assistants (PDA). Features include
network gateway, notification routing, security (SSL, IPSec, VPN), mobile device
support (WAP, SMS) and integration with Windows 2000.

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Module—A subunit of an assembly. Assemblies contain one or more modules, which
are DLLs that must be combined into assemblies to be used. The assembly manifest
(sometimes called a module manifest) describes all of the modules associated with
an assembly.

MSDE 2000 (Microsoft Data Engine)—A light weight release of the SQL Server 7.0
data engine. The MSDE is used as a relational data store on many Microsoft
products, including BizTalk Server 2000, Host Integration Server 2000, SQL Server
2000, Visual Studio.NET, and the .NET Framework. The MSDE a modern replacement
for the older Microsoft Jet database technology.

MSIL (Microsoft Intermediate Language)—The machine-independent language into
which .NET applications are compiled using a high-level .NET language compiler
(e.g., C# and VB.NET). The MSIL output is then used as the input of the Just-In-
Time (JIT) compiler, which compiles the MSIL instructions to machine language just
prior to its execution. MSIL can also be converted to native machine object code
using the Native Image Generator utility.

MSBuild—The build tool (MSBuild.exe) for Longhorn applications.

MSIL Assembler—A .NET programming tool (ILAsm.exe) used to create MSIL
portable executable (PE) files directly from MSIL code.

MSIL Disassembler—A .NET programming tool (ILDAsm.exe) used to translate a
portable executable (PE) file containing MSIL code to an an MSIL file that can be
used as input to MSIL Assembler.

Multi-module Assembly—A .NET program which is contained in many modules and
resource files. The use of an assembly manifest to identify all of the files in a multi-
module assembly is required.


Namespace—A logical grouping of the names (i.e., identifiers) used within a
program. A programmer defines multiple namespaces as a way to logically group
identifiers based on their use. For example, System.Drawing and System.Windows are two
namespaces containing each containing types used for for different purposes. The
name used for any identifier may only appear once in any namespace. A namespace
only contains the name of a type and not the type itself. Also called name scope.

Native code—Machine-readable instructions that are created for a specific CPU
architecture. Native code for a specific family of CPUs is not usable by a computer
using different CPU architectures (c.f., Intel x86 and Sun UltraSPARC). Also called
object code and machine code.

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Native Image Generator—A .NET programming tool (Ngen.exe) used to compile a
managed assembly to native machine code and install it in the local assembly cache.
During execution the native image will be used each time the assembly is accessed
rather than the MSIL assembly itself. If the native image is removed, the CLR reverts
to using the original MSIL assembly by default. Native images are faster to load and
execute than MSIL assemblies, which must be Just-In-Time (JIT) compiled by the
CLR. Using Ngen to create a native image file is often referred to as pre-JITting,
because it makes JIT-compiling the assembly unnecessary.

.NET Compact Framework—A port of the .NET Framework to Windows CE,
allowing embedded and mobile devices to run .NET applications. See Smart Device

.NET Data Provider—See Data provider.

.NET Enterprise Server product family—These products include Application
Center, BizTalk Server, Commerce Server, Content Management Server, Exchange
Server, Host Integration Server, Internet Security and Acceleration Server, SQL
Server 2000 , and Windows 2000 Server. Formerly known as BackOffice Server

.NET Framework—A programming infrastructure created by Microsoft for building,
deploying, and running applications and services that use .NET technologies, such as
desktop applications and Web services. The .NET Framework contains three major
parts: the Common Language Runtime (CLR), the Framework Class Library, and
ASP.NET. See .NET Compact Framework.

.NET Framework Class Library (FCL)—The foundation of classes, interfaces, value
types, services and providers that are used to construct .NET Framework desktop
and Web-based (i.e., ASP.NET) applications. The fundamental elements of the FCL
are defined as classes located in the System namespace. All of the most primitive
aspects of .NET are stored in System, including built-in value types, the Object type,
and support for exception handling and garbage collection. Thousands of more
classes are located in second- and third-level namespaces that include support for
network and file I/O, graphics, security, configuration management, and Web
services. All CLS-compliant compilers can use the FCL.

.NET Framework Configuration Tool—A .NET programming tool (Mscorcfg.msc)
used to adjust code access security policy at the machine, user, and enterprise
security policy levels. This tool can also be used to configure remoting services, and
add, configure, and delete assemblies in the Global Assembly Cache. See Global
Assembly Cache Utility.

.NET Services Installation Tool—A .NET programming tool (Regsvcs.exe) used to
add managed classes to Windows 2000 Component Services. This tool loads and
registers an assembly, generates, registers, and installs a type library into a
specified COM+ 1.0 application.

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NGSCB—Next-Generation Secure Computing Base—A virtual vault residing within
each computer that lets users store encrypted information and only authorize certain
entities to see it. It also provides protection for critical data against virus attacks,
Trojan horses and spyware and could double as a Digital Rights Management tool to
authenticate who is allowed to see a file or use a program.

NGWS—Next Generation Web Service—This was one of the pre-release names for
.NET before its release.


Object—The instance of a class that is unique and self-describing. A class defines an
object, and an object is the functional, realization of the class. Analogously, if a class
is a cookie cutter then the cookies are the objects the cutter was used to create.

Object type—The most fundamental base type (System.Object) that all other .NET
Framework types are derived from.

OLE (Object Linking and Embedding)—A Microsoft technology that allows an
application to link or embed into itself documents created by another type of
application. Common examples include using Microsoft Word to embed an Excel
spreadsheet file into a Word document file, or emailing a Microsoft Power Point file
as an attachment (link) in Microsoft Outlook. OLE is often confused with the
Component Object Model (COM), because COM was released as part of OLE2.
However, COM and OLE are two separate technologies.

Orcas—The code name for the version of Visual Studio .NET to be released near the
time Microsoft Longhorn is released. This follows the release of Visual Studio .NET

Overloading—Using a single identifier to refer to multiple methods that differ by
their parameters and/or return type.

Overriding—To supercede an instance field or virtual method in a base class with a
new definition of that field or method in the derived class.


Palladium—Former code name for Microsoft's Next-Generation Secure Computing
Base (NGSCB) project.

Pinned—A block of memory that is marked as unmovable. Blocks of memory are
normally moved at the discretion of the CLR, typically at the time of garbage

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collection. Pinning is necessary for managed pointer types that will be used to work
with unmanaged code and expect the data to always reside at the same location in
memory. A common example is when a pointer is used to pass a reference to a
buffer to a Win32 API function. If the buffer were to be moved in memory, the
pointer reference would become invalid, so it must be pinned to its initial location.

Pre-JIT compiler—Another name for the Native Image Generator tool used to
convert MSIL and metadata assemblies to native machine code executables.

Private assembly—An assembly that is used only by a single application. A private
assembly will run only with the application with which it was built and deployed.
References to the private assembly will only be resolved locally to the application
directory it is installed in. See Shared assembly.

Pointer—A variable that contains the address of a location in memory. The location
is the starting point of an allocated object, such as an object or value type, or the
element of an array.

Pointer types—See Managed pointer types, Unmanaged pointer types.

Portable Executable (PE) file—The file format defining the structure that all
executable files (EXE) and Dynamic Link Libraries (DLL) must use to allow them to
be loaded and executed by Windows. PE is derived from the Microsoft Common
Object File Format (COFF). The EXE and DLL files created using the .NET Framework
obey the PE/COFF formats and also add additional header and data sections to the
files that are only used by the CLR. The specification for the PE/COFF file formats is
available at

Portable Executable Verifier—A .NET programming tool (PEVerify.exe) used
to verify that a .NET compiler has created type-safe metadata and MSIL code.
Because Microsoft .NET compilers always generate type-safe code, this tool is used
primarily with third-party ILASM-based compilers to debug possible code generation

Pre-defined types—Types defined by the CLR in the System namespace. The pre-
defined values types are integer, floating point, decimal, character, and boolean
values. Pre-defined reference types are object and string references. See User-
defined types.

Primary Interop Assemblies (PIAs)—Assemblies that come with Microsoft Office
2003 that allow managed code (VB .NET, C#, etc.) to call Office code.

Property—A CLR language feature that allows the value of a single member variable
to be modified using getter and setter methods defined in a class or structure. See

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Qualified identifiers—Two or more identifiers that are connected by a dot
character (.). Only namespace declarations use qualified identifiers (e.g.,


R2—The codename for the Windows Server 2003 Update due in 2005.

Register Assembly Tool—Same as Assembly Registration Tool.

Register Services Utility—Same as .NET Services Installation Tool.

Reference types—A variable that stores a reference to data located elsewhere in
memory rather than to the actual data itself. Reference types include array, class,
delegate, and interface. See Value types, Pointer types.

Reflection—A feature that allows an application to query its own metadata.
Reflection (System.Reflection) allows an application to discover information about itself
so that it may display this information to the user, modify its own behavior by using
late-binding and dynamic invocation (i.e., binding to and calling methods at
runtime), or create new types at runtime (Reflection Emit). See Attribute-based

Remoting—A .NET technology that allows objects residing in different application
domains to communicate. Objects in different application domains are said to be
separated by a remoting boundary. Objects using remoting may be on the same
computer, or on different computers connected by a network. Remoting is the .NET
replacement for Distributed COM (DCOM). See Marshaling.

Resource—An addressable unit of data that is available for use by an application.
Resources include text strings, files, documents, vector drawings, bitmapped images,
binary data, data streams, message queues, and query result sets. In some
contexts, application services themselves, such as Web services, are referred to as

Resource File Generator Tool—A .NET programming tool (Resgen.exe) used to
convert the resource information stored in text files or XML .resx files to .resource files
that can be embedded in a runtime, binary executable, or compiled into satellite
assemblies using the Assembly Linking Utility.

Runtime Callable Wrapper (RCW)—A metadata wrapper that allows COM
components to be called from .NET applications. For OLE automation interfaces, an
RCW is a managed .NET assembly that is generated from the COM component's type
library using the Type Library Importer tool. For non-OLE automation interfaces, a

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custom RCW must be written that manually maps the types exposed by the COM
interface to .NET Framework-compatible types. See COM Callable Wrapper (CCW).

Runtime Debugger—A .NET programming tool (CorDbg.exe) used as a command-
line, source-level debugging utility for MSIL programs. See CLR Debugger.

Runtime host—A runtime environment used to manage the execution of program
code. Examples include the .NET Common Language Runtime and the Java Virtual
Machine (JVM).


Satellite assembly—An assembly that contains only resources and no executable
code. Satellite assemblies are typically used by .NET application to store localized
data. Satellite assembles can be added, modified, and loaded into a .NET application
at runtime without the need to recompile the code. Satellite assemblies are created
by compiling .resource files using the Assembly Linking Utility.

Saturn—the code name for the original ASP.NET Web Matrix product.

Seamless Computing—A term indicating that a user should be able to find and use
information effortlessly. The hardware and software within a system should work in
an intuitive manner to make it seamless for the user. Seamless computing is being
realized with the improvements in hardware (voice, ink, multimedia) and software.

Secure Execution Environment (SEE)—A secure, managed-code, runtime
environment within the Microsoft Longhorn Operating System that helps to protected
against deviant applications. This is a part of Microsoft's "Trustworthy Computing"

Serialization—The conversion of an object instance to a data stream of byte values.
Serialization is performed by the CLR and occurs when an object must be converted
to a persistent form to be stored in an information retrieval system (e.g., a
database), on media (e.g., a file on a disk), or when marshaled across a context,
application domain, process, or machine boundary.

Server—A computer program or system that provides information or services
requested by a client. See Client/Server architecture.

Server-side—An operation or event that occurs on a server system. Examples
include server-side scripting, server-side objects, and server-side processing. See

Service—An application that provides information and/or functionality to other
applications. Services are typically non-human-interactive applications that run on
servers and interact with applications via an interface. A service may expose a
synchronous, programmatic interface (i.e., an API), allowing it to be tightly-coupled

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with a consumer, or use asynchronous, message-based communications (e.g., HTTP,
XML, and SOAP) to remain very loosely-coupled with consumers. Services are an
essential part of distributed architecture program design.

SGML (Standard Generalized Markup Language)—The standard markup language
used by the publishing industry to specify the format and layout of both paper and
electronic documents. SGML is very flexible and feature-rich, and it is very difficult to
write a full-featured SGML parser. As a result, newer markup languages requiring
fewer features (e.g., HTML and XML) are subsets of SGML. SGML is defined by the
international standard ISO 8879.

Shared assembly—An assembly that can be referenced by more than one
application. Shared assemblies must be built with a strong name and are loaded into
the Global Assembly Cache. See Private assembly.

Shared name—Same as a strong name. Also called published name.

Shared name utility—A .NET programming tool (Sn.exe) used to verify assemblies
and their key information and to generate key files. This utility is also used to create
strong names for assemblies.

Side-by-Side Execution—Running multiple versions of the same assembly
simultaneously on the same computer, or even in the same process. Assemblies
must be specifically (and carefully) coded to make use of side-by-side execution.

Single-module assembly—A .NET program in which all components are combined
into a single DLL or EXE file. Such an assembly does not require an assembly

Smart Device Extensions (SDE)—An installable SDK that allows Visual Studio .NET
1.0 to be used for developing .NET application for the Pocket PC and other handheld
devices that support the Microsoft Windows CE .NET operating system and the
Microsoft .NET Compact Framework. SDE will be fully integrated into Visual Studio
.NET 2003.

SOAP (Simple Object Access Protocol)—A lightweight, XML-based messaging
protocol used to encode the information in Web service request and response
messages before sending them over a network. SOAP messages are independent of
any operating system or protocol, and may be transported using a variety of Internet
protocols, including SMTP, MIME, and HTTP.

SoapSuds Tool—A .NET programming tool (SoapSuds.exe) used to create XML
schemas for services in a .NET assembly, and to create an assembly from an XML
schema. This tool is used primarily to compile client applications that communicate
with XML Web services using remoting.

SQL Server 2000—Microsoft's enterprise-scale relational database and member of
the .NET Enterprise Server product family.

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Stack—An area of program memory used to store local program variables, method
parameters, and return values. In .NET languages, value types are allocated on the
stack. See Heap.

Static fields—Types that declare member variables which are associated with a
type rather than an instance of the type. Static fields may be access without first
instantiating their associated type.

Starlite—A code name for the original Microsoft .NET Compact Framework

Static methods—Types that declare methods which are associated with a type
rather than an instance of the type. Static methods may be called without first
instantiating their associated type.

Strong name—An assembly name that is globally unique among all .NET
assemblies. A public key encryption scheme is used to create a digital signature to
insure that the strong name is truly different than all other names created at
anytime and anywhere in the known universe. The digital signature also makes it
easy to encrypt the assembly, authenticate who created the assembly, and to
validate that the assembly hasn't been corrupted or tampered with. Strong names
are created using the Shared name utility.

Strongly-typed—A programming language is said to be strongly-typed when it pre-
defines specific primitive data types, requires that all constants and variables be
declared of a specific type, and enforces their proper use by imposing rigorous rules
upon the programmer for the sake of creating robust code that is consistent in its

Structure—In .NET languages, structures are light-weight classes that are simpler,
have less overhead, and are less demanding on the CLR. Structures are typically
used for creating user-defined types that contain only public fields and no properties
(identical to structures in the C language). But .NET structures, like classes, also
support properties, access modifiers, constructors, methods, operators, nested
types, and indexers. Unlike classes, however, structures do not support inheritance,
custom constructors, a destructor (or Finalize) method, and no compile-time
initialization of instance fields. It is important to note that a structure is a value type,
while classes are a reference type. Performance will suffer when using structures in a
situation where references are expected (e.g., in collections) and the structure must
be boxed and unboxed for it to be used.

Stylesheets—Data files used to express how the structured content of a document
should be presented on a particular physical medium (e.g., printed pages, Web
browser, hand-held device, etc.). Details of the presentation include font style, lay
out, and pagination. Also called templates.

System Definition Model (SDM)—An XML document that follows a system
throughout its life and is kept updated as a system moves from the initial design and
development stages through its lifecycle and into maintenance. The SDM defines a
system, which includes hardware and software resources. It includes a means for the

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system to compose other systems and subsystems, expose its endpoints for
communication purposes, and document its configuration requirements. When
initially created, an SDM document can be a simple, skeletal view of a system.
Additional information can be added to flesh out semantics, such as server
configuration information, security and connection policies, service level agreements,
health models, and other information. (From An Overview of Microsoft's Whitehorse.)


Talisker—The pre-release code name for Windows CE .NET (a.k.a., Windows CE

Throwing—When an abnormal or unexpected condition occurs in a running
application, the CLR generates an exception as an alert that the condition occurred.
The exception is said to be thrown. Programmers can also programmatically force an
exception to be thrown by the use of the throw statement. See Exception Handling.

Trustbridge—A directory-enabled middleware that supports the federating of
identities across corporate boundaries.

Try/Catch block—An exception handling mechanism in program code. A try block
contains a set of program statements that may possibly throw an exception when
executed. The associated catch block contains program statements that handle any
exception that is thrown in the try block. Multiple catch blocks may be defined to
catch specific exceptions (e.g., divide by zero, overflow, etc.). See Finally block.

Type-safe—Code that accesses only the memory locations it is authorized to access,
and only in well-defined, allowable ways. Type-safe code cannot perform an
operation on an object that is invalid for that object. The C# and VB.NET language
compilers always produce type-safe code, which is verified to be type-safe during
JIT-compilation. The PEVerify tool can also be used to verify if code is type-safe.

Types—A set of data and function members that are combined to form the modular
units used to build a .NET applications. Pre-defined types exist within the CLR and
user-defined types are created by programmers. Types include enumerations,
structures, classes, standard modules, interfaces, and delegates. See Type

Type library—A compiled file (.tlb) containing metadata that describes interfaces
and data types. Type libraries can be used to describe vtable interfaces, regular
functions, COM components, and DLL modules. Type libraries are compiled from
Interface Definition Language (IDL) files using the MIDL compiler.

Type Library Exporter—A .NET programming tool (TlbExp.exe) used to create a
COM type library file based on the public types defined within a specified .NET

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Type Library Importer—A .NET programming tool (TlbImp.exe) used to create a
managed .NET assembly from a COM type library by mapping the metadata-
encoded definitions to the appropriate .NET types.

Type members—Same as class members.

Typelib—A type library.


UDDI (Universal Description, Discovery, and Integration)—An XML- and SOAP-
based lookup service for Web service consumers to locate Web Services and
programmable resources available on a network. Also used by Web service providers
to advertise the existence of their Web services to consumers.

Unboxing—Conversion of a reference type object (i.e. System.Object) to its value
type instance. Unboxing must be explicitly performed in code, usually in the form of
a cast operation. See Boxing.

Unmanaged—An adjective generally applied to any code or data that is outside of
the control of a runtime host environment. In .NET, any objects or resources not
allocated and controlled by the CLR are considered unmanaged (e.g., Windows
handles and calls to the Win32 API).

Unmanaged code—Any code that executes outside of the control of the .NET
Common Language Runtime. Unmanaged code may perform unsafe operations, such
as declare and operate on pointers, take the address of a variable, and perform
conversions between pointers and integral types. Uses of unmanaged code include
calling operating system APIs, interfacing to COM components, accessing
unmanaged areas of memory, and writing performance-critical routines that are not
encumbered by the overhead of the CLR. Also called unsafe code.

Unmanaged data—Data (i.e. memory) that is allocated outside of the control of the
CLR. Unmanaged data can be access by both managed and unmanaged code.

Unmanaged pointer types—Any pointer type that is not managed by the CLR.
That is, a pointer that store a reference to an unmanaged object or area of memory.

Unmanaged resources—Objects created and manipulated outside of the control of
the CLR. Examples includes file handles opened using the Win32 API, and database
connections obtained using ODBC.

Unsafe—Same as unmanaged.

User-defined types—Reference (object) types defined in code by a programmer.
See Pre-defined types.

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Value types—A variable that stores actual data rather than a reference to data,
which is stored elsewhere in memory. Simple value types include the integer,
floating point number, decimal, character, and boolean types. Value types have the
minimal memory overhead and are the fastest to access. See Reference types,
Pointer types.

Variable—A typed storage location in memory. The type of the variable determines
what kind of data it can store. Examples of variables include local variables,
parameters, array elements, static fields and instance fields. See Types.

Version number—See Assembly version number.

Vienna—Code name for the Microsoft Office Live Communications Server 2005 (LCS
2005) beta.

Visual Basic .NET (VB.NET)—A Microsoft-supported language for the .NET
Framework. VB.NET is the "next generation" release of the very popular Visual Basic
programming language (a.k.a., VB7).

Visual C++ .NET—A Microsoft-supported language for .NET Framework. Visual C++
.NET allows developers to use the C++ language to write managed applications, and
to easily migrate legacy C++ code to the .NET Framework. Code written in Visual
C++ .NET is also referred to as managed C++; code written in the legacy Visual
C++ language is sometimes referred to as unmanaged C++.

Visual Studio .NET (VS .NET)—A full-featured, Interactive Development
Environment (IDE) created by Microsoft for the development of .NET applications. VS
.NET makes a better alternative to Visual Notepad for creating .NET applications.
Officially called Microsoft Visual Studio .NET 2002.

Visual Studio .NET 2003 (VS .NET)—The second version of Visual Studio .NET that
was also known by the code name Everett.

Visual Studio 2005(VS .NET)—The third version of Visual Studio .NET that was also
known by the code name Whidbey. This version is due to release in 2005.

Visual Studio Team System 2005 (VS .NET)—A high-end skew for Visual Studio
2005. This version includes enterprise-level tools and more. Codename for this
product was known as "Burton".


Web Form—A .NET Framework object that allows development of Web-based
applications and Web sites. See Windows form.

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The Web Matrix Project—A free WSIWIG development product (IDE)for doing
ASP.NET development that was released as a community project. The most recent
version—The Web Matrix Project (Revisited)—can be found here.

Web service—An application hosted on a Web server that provides information and
services to other network applications using the HTTP and XML protocols. A Web
service is conceptually an URL-addressable library of functionality that is completely
independent of the consumer and stateless in its operation.

Web service consumer—An application that uses Internet protocols to access the
information and functionality made available by a Web service provider. See Web

Web Service Protocols—Open communication standards that are key technologies
in the .NET Web Services architecture. These protocols include WSDL, HTTP, XML,

Web Service Platform—This was one of the pre-release names for the original
Microsoft .NET Framework. See also COM+ 2.0.

Web service provider—A network application that uses Internet protocols to
advertise and provide services to Web service consumers. See Web service.

Web Services Description Language (WSDL)—An XML-based contract language
for describing the network services offered by a Web service provider via UDDI.
WSDL describes a Web service to Web service consumers by its public methods, data
types of all parameters, return value, and bindings. WSDL will eventually replace
Microsoft's earlier Web Services discovery protocol, DISCO. See the document Web
Services Description Language (WSDL) 1.1.

Web Services Description Language Tool—A .NET programming tool (Wsdl.exe)
used to create service descriptions and generate proxies for ASP.NET Web service

Web Services Discovery Tool—A .NET programming tool (Disco.exe) used to
locate the URLs of XML Web services located on a Web server, and save the
information related to the resources of each XML Web service to a set of files. These
files can be used as input to the Web Services Description Language Tool to create
XML Web service clients. See DISCO.

Whidbey—The pre-release code name for the "next generation" release of Visual
Studio after Everett and prior to Longhorn.

Whistler—The pre-release code name used for Windows XP.

Whitehorse—The code name for the set of modeling tools included in Micrsoft
Visual Studio 2005 ("Whidbey"). See An Overview of Microsoft's Whitehorse.

Windows 2000 Server—The central server operating system of the Microsoft

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BackOffice Server 2000 product family. Windows 2000 Sever (also known as
Windows NT 5) is the successor of Windows NT Server 4.0 and will be replaced by
Windows Server 2003.

Windows Forms Class Viewer—A .NET programming tool (WinCV.exe) used to
search for and display the namespace and class information within an assembly.

Windows Forms Resource Editor—A .NET programming tool (Winres.exe) used to
help a programmer modify localization information in a Windows Form.

Windows Form—A .NET Framework object that allows the development of
"traditional" Windows desktop applications. Also called WinForms. See Web Form.

Windows Installer—The software installation and configuration service for
Windows 2000 and Windows XP. Most .NET applications can be successfully deployed
using XCOPY. However, if a deployment requires complex tasks, such as changes in
system configuration, creation of user, groups, or folders, etc., Windows Installer
must be used. Windows Installer 2.0 is required for use by the .NET Framework; it is
also available for Windows 9x and Windows NT.

Windows .NET Server 2003—The original name of Windows Server 2003. The
".NET" was dropped as part of an attempt to remarket the concept of .NET not as a
product, but instead as a business strategy.

Windows Server 2003—The next generation of Windows 2000 Server that offers
tighter integration with the .NET Framework, and greater support for Web services
using Internet Information Server 6.0 and XML and UDDI services. This product was
formerly known as Windows .NET Server 2003.

WinFS—("Windows Future System") The code name for the new type-aware,
transactional, unified file system and programming model that will be a key part of
Longhorn. WinFS allows various kinds of data and information stored on your
machine to be associated and categorized. You can associate relationships between
information and these associations can be used to access what is stored on your

WinFX—The new Windows API that will be released with the Microsoft Longhorn
Operating System. This will include features for Avalon, Indigo, and WinFS as well as
a number of fundamental routines.

WPO—Whole Program Optimization—This is an optimization that can be done by the
C++ compiler. All object modules are viewed at once before generating code, which
allows for additional optimizations to be performed.

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XAML—(Extensible Application Markup Language) The declarative markup language
for Longhorn that allows an interface to be defined. Longhorn applications can be
created by using XAML for the interface definition and managed procedure code for
other logic.

XCOPY—An MS-DOS file copy program used to deploy .NET applications. Because
.NET assemblies are self-describing and not bound to the Windows registry as COM-
based application are, most .NET applications can be installed by simply being copied
from one location (e.g., directory, machine, CD-ROM, etc.) to another. Applications
requiring more complex tasks to be performed during installation require the use of
the Microsoft Windows Installer.

XDR (XML Data-Reduced)—A reduced version of XML Schema used prior to the
release of XML Schema 1.0.

XDA—A consolidated development environment that allows programs to be created
for Windows, XBoxes, and more.

XHTML (eXtensible HyperText Markup Language)—The next generation of HTML.
HTML was originally designed to display data; XML was specifically designed to
describe data. XHTML is a combination of all the elements in HTML 4.01 with the the
syntax of XML. Although nearly identical to HTML, XHTML has much stricter rules and
is cleaner in its syntax, thus resulting in well-formed Web pages that are more
portable across a wide range of Web browsers.

Xlink (XML Linking Language)—A language that allows links to other resources to
be embedded in XML documents, similar to the hyperlinks found in HTML Web
pages. See the document XML Linking Language (XLink) Version 1.0.

XML (eXtensible Markup Language)—A meta-markup language that provides a
format for describing almost any type of structured data. XML is a subset of SGML
and has become the standard language for storing, viewing, and manipulation Web-
based data. XML allows the creation of custom tags to describe both proprietary data
and business logic. See the document Extensible Markup Language (XML) 1.0
(Second Edition).

XML Schema—A description of the structure of an XML document. Schemas are
written in XSD and support namespaces and data types.

XML Schema Definition Tool— A .NET programming tool (Xsd.exe) used to
generate XML schemas (XSD files) from XDR and XML files, or from class information
in an assembly. This tool can also generate runtime classes, or DataSet classes, from
an XSD schema file.

XML Web services—Web-based .NET applications that provide services (i.e., data

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and functionality) to other Web-based applications (i.e. Web service consumers).
XML Web services are accessed via standard Web protocols and data formats such as

XPath (XML Path Language)—A language that uses path expressions to specify the
locations of structures and data within an XML document. XPath information is
processed using XSLT or XPointer. See the document XML Path Language (XPath)
Version 1.0.

XPointer (XML Pointer Language)—A language that supports addressing into the
internal structures of XML documents. XPointer allows the traversals of an XML
document tree and selection of its internal parts based on element types, attribute
values, character content, and relative position. XPointer is based on the XML Path
Language (XPath). See the document XML Pointer Language (XPointer).

XSD (XML Schema Definition)—A language used to describe the structure of an XML
document. XSD is used to defined classes that are in turn used to create instances of
XML documents which conform to the schema. See the document XML Schema Part
0: Primer.

XSL (eXtensible Stylesheet Language)—A language used for creating stylesheets for
XML documents. XSL consists of languages for transforming XML documents (XPath
and XSLT) and an XML vocabulary for specifying formatting semantics. See the
document Extensible Stylesheet Language (XSL) Version 1.0.

XSLT (eXtensible Stylesheet Language Transformation)—A language for
transforming XML documents into other XML documents based of a set of well-
defined rules. XSLT is designed for use as part of XSL. See the document XSL
Transformations (XSLT) Version 1.0.

XQL (XML Query Language)—A query language used to extract data from XML
documents. XQL uses XML as a data model and is very similar to the pattern
matching semantics of XSL. See the document XML Query Language (XQL).


Yukon—The code name for the release of Microsoft SQL Server 2003 (a.k.a., SQL
Server 9). Yukon offers a tighter integration with both the .NET Framework and the
Visual Studio .NET IDE. Yukon will include full support for ADO.NET and the CLR,
allowing .NET languages to be used for writing stored procedures.


No entries.

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