Objects Within a Database

Objects Within a Database

1. Queries

   • Used to answer questions about the data. Can extract and display records which match certain criteria
   • Can be used to view, alter and analyse data from one or more tables in a database
   • Can be used as a source of records in forms or reports
   • Only the required data is displayed
   • Can be saved for future use
   • For example, in a customer database, a company could use a query to find and view only the customers who live in Scotland and have purchased something in the last moth
   • Criteria
     • Wildcard symbols and maths operators can be used. Examples include:
       • Or
       • > (Greater than) and < (Less than)
       • And
     • Criteria can be combined, e.g. >25 and <50
     • Wildcard can be used
       • *: Matches any number of characters or none
       • ?: Matches exactly on echaracter

2. Reports

   • Used to format the output of data from tables or queries in a user friendly way - mainly for printing

3. Forms

   • Used to input and/or output data in a user friendly way - for on-screen use
   • Why use forms?
     • Easily created using 'Wizards'
       • The best approach is to create the basic form using the Wizard, then modify it as needed
     • Forms can be used to both input and output data records
     • Allows records to be presented in a user friendly way
     • Text can be enhanced and additional text can be added
     • Allows command button to be added
     • Can be editied using a form editor
   • Using Forms
     • You can view your data in a form and you can also:
       • Add records
       • Modify records
       • Delete records
     • When you move off the record, the changes are made automatically to the table
     • Note: Be careful when deleting records