OpenEdge Development:<br />Programming Interfaces Reporting information from two tables

Release 10.1A: OpenEdge Development:
Programming Interfaces

Reporting information from two tables

The next step is to look at the orders for each selected customer. This information is in the Order table. Another FOR EACH inside the first accomplishes this task. For each iteration of the outer block, the inner block finds all the related information. The WHERE clause establishes the relationship between the two tables.

The code below from i-10-07.p shows the nested FOR EACH blocks:
i-10-07.p
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  FOR EACH Customer FIELDS (Balance Credit-Limit Name Contact Cust-Num)
      WHERE Balance >= (Credit-Limit * .85) 
      WITH STREAM-IO:
      DISPLAY Name FORMAT "x(20)" Contact FORMAT "x(15)" 
          Balance Credit-Limit WITH NO-BOX.
                
      FOR EACH Order FIELDS (Cust-Num Order-Num Order-Date Ship-Date
          Promise Date) WHERE Order.Cust-Num = Customer.Cust-Num 
          WITH STREAM-IO:
          DISPLAY Order-Num Order-Date Ship-Date 
              Promise-Date SKIP(1) WITH 2 COLUMNS.
      END.
  END.
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The output from this procedure (following) shows how the related information ends up grouped together:

Notice that for a single iteration of the Customer data, there may be several iterations of Order data. Earlier you learned that the default frame of an iterating control block is a down frame. When you nest control blocks, only the innermost block uses a down frame. The other blocks execute one iteration at a time. This default behavior lets the related information group together naturally with the iteration of the blocks.