Deriving Views › Defining Views

Defining Views

The Steps

Defining a view involves some or all of the following steps:

1. Naming the view
2. Identifying the source table(s) and join criteria
3. Choosing columns
4. Defining additional columns
5. Selecting rows
6. Generating the view

Example, Continued

To illustrate the steps involved in defining a view, the example presented in the chapter "Creating and Using Stored Tables" will be continued. In that chapter, you created the JOB and APPLICANT tables for the employment application that Fran Snell is developing for the personnel office of Acme Insurance. In this sample application, you will use those stored tables to derive the JOBS AND APPLICANTS view. This view will match applicants with open positions at Acme Insurance. To derive this view, you will perform the following relational operations:

• Join the JOB and APPLICANT tables based on position name.
• Project the desired columns.
• Select the positions that are open.

Follow steps 1 through 6 outlined below to derive the JOBS AND APPLICANTS view.