Introduction to Databases

							Introduction to Databases

     Calera High School
        Dawn Bone
       What is a Database
• An organized set of stored information
  usually on one topic
• Information is stored in tables
       Capabilities of a Database
•   Add or delete data within a file
•   Search a file for certain data
•   Update or change data in a file
•   Sort data in some order
    – Numeric or Alphabetic
• Print all or part of the data
• Create a query
• Create a report
       Basics of a Database
• Databases are made up of
  – Fields
  – Records
  – Files
                               Record
              Field




                        File
                     Fields
• A field is each separate piece of information
  (but related) in a record. Fields are the
  “building blocks” for records containing the data
  you want to store, find, sort and print
• Example
   –   Name
   –   Address
   –   City
   –   Phone #         This record has four fields
                       Records
• A record is a collection of data about a
  single product, activity, or transaction
   – Example
      • Titanic
      • L. Douglas Wilder
      • Person in the address book



This record is about
Sue Miller
                     Files
• A file is a collection of related database
  information
  – Example
     • A video collection
     • Famous Alabamians
     • Address Book
      Defining the Structure –
         the first step in creating a database file

•   Decide what fields will be included
•   Name each field
•   Define field type
•   Define field size
                       Data Types
• Each field holds a different type of information.
  There are 10 different types of data
Text – text or numbers like phone # or zip code, maximum of 50 characters
Memo – notes, descriptions or summaries – maximum of 64,000 characters
Number – numbers you calculate
Date/Time – date and time only
Currency – money only
Auto # - computer automatically assigns a number
Yes/No – can answer yes/no or true/false questions
OLE object – can insert a picture, sound or file
Hyperlink – can jump to a document or web page
Lookup Wizard – can produce a “drop down” menu of choices
    Importance of Field Types
• If you are entering a phone number with a dash,
  it could not be added into a field that has the
  number data type because the dash isn’t a number
• If you are sorting numerically, but the data type
  for the numbers are 1, it will group all the 1s
  together
• If you are creating a query or filter for a date, but
  you gave the date a text data type, it will not be
  able to correctly filter that field
Business Uses of Databases
 Employee records
 Inventory
 Keep a list of customers
 Payroll
Government Uses of Databases
•   Social Security accounts
•   Police – criminals, felonies, etc
•   Population
•   Voter records
      Home Uses of Databases
•   Create an address book
•   Record collections (coin, stamp, cd, etc)
•   Personal Records
•   Cookbooks
 Specialized Uses of Databases
• Pharmacies – drug and patient information
• Creating mass mailing lists
• Recruiting
  Popular Database Packages
• Microsoft Access
• File Maker Pro
• Oracle
Components of an Access Database

•   There are six components to an Access database.
•   Tables
•   Queries
•   Forms
•   Reports
•   Macros
•   Modules
(macros and modules are for advanced users so we will not discuss those)
          Creating Tables
• You can create a table in design view.
                 Design View
• This is where you start off. It allows you to add fields,
  change field size and choose data type
• This view allows you to see the structure or the
  blueprint of the table or form.
           Datasheet View
• This allows you to see several records a the
  same time. It displays the data in columns
  and rows.
• You actually enter the data for your
  records here!!!!!!!!
                 Tables
• A table is a collection of related data
  that is stored in columns and rows.
• Table view and datasheet view are the
  same thing
         Tables - formatting
• To format columns to fit the longest entry,
  highlight all the columns, go to format,
  column width, and choose best fit.
                   Filters
• Filter means to separate
• Three types of filters
  – Filter by selection – one field, one criteria
  – Filter by form – more than one field, but only
    one criteria for each
  – Advanced filter – more than one field,
    multiple criteria for each, and can include
    advanced searches (math symbols)
                     Queries
• A query is a stored question about data in
  your table. It asks the database to find specific
  information to meet the conditions you asked for.




• In this query I asked it to list all of the students
  who were walkers.
                 Wildcards
• Wildcards can be used to substitute for
  unknown characters
   – * - a group of characters
   – ? – a single character
• To find records that start with the letter S,
  you would search for S*
• To find records that end with the letter S,
  you would search for *S
          Filters vs Queries
• Differences between filters and queries
  – You can save a query, you cannot save a filter
  – In a query, you choose which fields to display,
    in a filter, you get all fields
                      Forms
• Forms provide a quick way to view, enter, and
  change information in a database
• This is another way to enter records into a table.
                    Reports
• A database
  report presents
  information
  retrieved from
  a table or
  query in a
  preformatted,
  attractive
  manner.
            Sorting
• To arrange
   – Ascending
   – Descending
• This table is sorted by last name