The examples in this section were originally written for an IBM mainframe environment, using DB2 as the database and IBM REXX as the language for the SQL generator. The first end user screen, shown in Figure 4.15, allows a user to choose a type of query. The end user is presented with a list of predefined reports. In this fashion, end users may choose from a set of report templates.

Figure 4.15  A screen to choose a report type.

After choosing the type of report desired, the next screen appears. This screen allows the entry of variance criteria (see Figure 4.16). The selected variance is used in the WHERE clause of the SQL SELECT statement, and this screen will be interrogated by the routine to generate the SQL. Note that the warehouse allows queries that compare one specific month with another specific month. This makes it very easy to compare two periods of time.

Figure 4.16  A screen used to choose variance criteria.

Figure 4.16 shows a sample data selection screen as it could be filled out by a user. The next screen, shown in Figure 4.17, allows end users to choose specific data attributes to limit a query. The end user may select a specific store, all stores in a city, or all stores within a standard metropolitan statistical area (SMSA). This screen also allows end users to constrain a query by a range of ZIP codes or a number of transactions during a chosen period. Each constraint is added to the WHERE clause with an AND condition.