Data Flow Diagram for Web Application - PowerPoint

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					            Chapter 1
Identifying the Applications and
     the Database Schema




    Oracle9i Developer: Developing Web Applications with Forms Builder   1
In this chapter you will:

• Learn how Oracle Forms Builder is integrated into the
  system development life cycle
• Use data flow diagrams to identify applications,
  processes, and the data needed for the processes
• Use entity relationship diagrams to initiate the design of
  the database schema
• Use the data schema diagram to identify the database
  properties
• Learn how Forms Builder uses the Oracle9i database




               Oracle9i Developer: Developing Web Applications with Forms Builder   2
Integration of Oracle Forms Builder into the
      System Development Life Cycle
• The system development life cycle (SDLC) consists of a
  series of phases that describe the life of an information
  system.

• Phases are:
    Project identification and selection
    Project initiation and planning
    Analysis
    Logical design
    Physical design
    Implementation
    Maintenance

            Oracle9i Developer: Developing Web Applications with Forms Builder   3
Integration of Oracle Forms Builder into the
      System Development Life Cycle

• Rapid application development (RAD) is a subset of the
  SDLC phases.

• RAD enables a developer to implement a system in a
  shorter time period than traditional methods.

• Forms Builder 9i is a development tool that supports both
  the traditional and RAD approaches.




            Oracle9i Developer: Developing Web Applications with Forms Builder   4
Integration of Oracle Forms Builder into the
      System Development Life Cycle
• Systems have three types of applications:

    Forms or screens
    Reports
    Processes that run without being seen by a user

• Forms Builder 9i is used to develop forms.

• Forms Builder 9i allows the developer to prototype forms
  early in the SDLC.



             Oracle9i Developer: Developing Web Applications with Forms Builder   5
Integration of Oracle Forms Builder into the
      System Development Life Cycle

• Prototyping is a RAD approach that helps the designer
  identify system requirements.

• Designer 9i is another Oracle tool used in the analysis
  and design phases.




            Oracle9i Developer: Developing Web Applications with Forms Builder   6
Integration of Oracle Forms Builder into the
      System Development Life Cycle
• Designer 9i is a computer-aided software engineering
  (CASE) tool. It is used to:

    Develop data flow diagrams
    Create entity relationship diagrams
    Generate data schema diagrams
    Generate data definition language (DDL) commands
     needed to create the database objects
    Generate form modules containing the data items
     needed by the form



           Oracle9i Developer: Developing Web Applications with Forms Builder   7
Integration of Oracle Forms Builder into the
      System Development Life Cycle




         Oracle9i Developer: Developing Web Applications with Forms Builder   8
   Using Data Flow Diagrams to Identify
    Application, Processes, and Data
• Before a developer can begin a form, the developer must
  first identify the following:

      The needed forms
      The data elements needed on the form
      The data elements that are output from the form
      Business rules that affect the data
      Tables that support the data structure




            Oracle9i Developer: Developing Web Applications with Forms Builder   9
   Using Data Flow Diagrams to Identify
    Application, Processes, and Data
• A data flow diagram is a good place to start.

• The purpose of a data flow diagram is to identify the
  processes in a system and the data that flows in and out
  of the process.

• Processes that require interaction by an operator will
  require a form.




            Oracle9i Developer: Developing Web Applications with Forms Builder   10
    Using Data Flow Diagrams to Identify
     Application, Processes, and Data
• Data flow diagrams consist of four symbols:

    External entity (source or sink) – Something outside
     the system that sends in or receives data
    Process – An action performed in the system
    Data flow -- Data moving into or out of a process
    Data store -- Data at rest




            Oracle9i Developer: Developing Web Applications with Forms Builder   11
   Using Data Flow Diagrams to Identify
    Application, Processes, and Data
• A form’s data needs can be identified by reviewing the
  process’ incoming and outgoing data flows.

• Data flow documentation consists of the data elements
  contained in the flow as well as the entity associated with
  the data elements.




           Oracle9i Developer: Developing Web Applications with Forms Builder   12
Using Data Flow Diagrams to Identify
 Application, Processes, and Data




     Oracle9i Developer: Developing Web Applications with Forms Builder   13
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
• Before a form can be built the database must be
  designed.

• An entity relationship diagram (ERD) is the tool used to
  design and depict the conceptual design of the database.

• Database elements are associated with an entity.

• The set of entity attributes describes or models the entity.




            Oracle9i Developer: Developing Web Applications with Forms Builder   14
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Entities are then associated with other entities. This
   shows how they are related.

 • Entities will eventually be turned into a table.

 • An entity instance relates to a record in a table.




             Oracle9i Developer: Developing Web Applications with Forms Builder   15
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • There are three type of entities:

     Regular entity
     Weak entity
     Associative entity




             Oracle9i Developer: Developing Web Applications with Forms Builder   16
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Regular entities exist on their own. (Student)

 • Weak entities must have a parent. (Courses offered,
  parent is Courses)

 • Associative entities relate two entities in a many to many
  relationship. (Courses Taken relates Students with the
  Courses Offered)




            Oracle9i Developer: Developing Web Applications with Forms Builder   17
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




        Oracle9i Developer: Developing Web Applications with Forms Builder   18
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Regular and weak entities are often shown on a form in a
   master-detail layout.

 • The master form section contains unique entity instances.
   (Student)

 • The detail form section contains repeating weak entity
   instances. (Courses Taken)

 • Records in the master-detail layouts are related through
   primary and foreign keys.

            Oracle9i Developer: Developing Web Applications with Forms Builder   19
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
• An entity must have an identifier. The identifier must
  have these features:

    Value must be unique
    Value must not be changeable
    Identifier must always contain a value

• Regular entities should have an identifier consisting of
  one data element.




            Oracle9i Developer: Developing Web Applications with Forms Builder   20
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema

• Weak entities generally have an identifier consisting of
  multiple data elements. One of which is the foreign key.

• A foreign key is a value that is the primary key in another
  entity.

• Entities represent the actual databases tables.




            Oracle9i Developer: Developing Web Applications with Forms Builder   21
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Entities (and tables) are related to each other.

 • ERDs depict three types of relationships.

     Unary - an entity is related to itself (i.e. an
      Employee is managed by another employee)
     Binary - an entity is related to one other entity (i.e. a
      Student has Courses Taken)
     U-nary - an entity is related to several different
      entities



             Oracle9i Developer: Developing Web Applications with Forms Builder   22
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




        Oracle9i Developer: Developing Web Applications with Forms Builder   23
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Entity or table relationships have two important
   properties. These are:

     Cardinality
     Ordinality




            Oracle9i Developer: Developing Web Applications with Forms Builder   24
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Cardinality indicates the number of related instances. A
   Student can have many Courses Taken instances.
   However, a Courses Taken instance can only have one
   Student.

 • Ordinality indicates whether an instance of the related
   entity must occur. A Student instance can occur with a
   Courses Taken instance. However, a Courses Taken
   instance cannot exist without a Student instance.




            Oracle9i Developer: Developing Web Applications with Forms Builder   25
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




         Oracle9i Developer: Developing Web Applications with Forms Builder   26
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
• Designer 9i has the ability to create a data schema
  diagram from the entity relationship diagram.

• Designer 9i has forms used to document the data
  elements in each entity.

• Designer 9i has forms used to document the entities that
  support the data flow.

• Designer 9i takes the entity information and creates the
  data schema diagram, the tables, and the table
  constraints.
            Oracle9i Developer: Developing Web Applications with Forms Builder   27
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




        Oracle9i Developer: Developing Web Applications with Forms Builder   28
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




        Oracle9i Developer: Developing Web Applications with Forms Builder   29
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




         Oracle9i Developer: Developing Web Applications with Forms Builder   30
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




        Oracle9i Developer: Developing Web Applications with Forms Builder   31
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema




         Oracle9i Developer: Developing Web Applications with Forms Builder   32
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema
 • Forms Builder has wizards that grab information from the
   database when creating forms.

 • Forms Builder gives form items their names based upon
   the corresponding database table column.

 • Forms Builder sets the data type and length of all data
   items based on the database table columns.




            Oracle9i Developer: Developing Web Applications with Forms Builder   33
   Using Entity Relationship Diagrams to
Initiate the Design of the Database Schema

 • Forms Builder ensures NOT NULL constrained form items
   have the Required property set to YES.

 • Forms Builder identifies the primary and foreign key
   columns when creating master-detail forms.




            Oracle9i Developer: Developing Web Applications with Forms Builder   34
Where You Are and Where You’re Going
• You have briefly reviewed the system development life
  cycle.

• You have seen how Oracle Forms Builder fits within this
  life cycle.

• You have seen how data flow diagrams are used to
  identify applications processes and data.

• You were introduced to entity relationship diagrams and
  data schema diagrams.

• You saw how Forms Builder uses the Oracle9i database.

          Oracle9i Developer: Developing Web Applications with Forms Builder   35
Where You Are and Where You’re Going

• In the next chapter you will be introduced to Forms
  Builder.

• You will learn how to build and execute a form.

• You will learn how to use wizards to create a simple form.




           Oracle9i Developer: Developing Web Applications with Forms Builder   36

				
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Description: Data Flow Diagram for Web Application document sample