Understanding Subqueries


Concept


Steps:

  1. You use subqueries to compare the value for a field in the primary query to the results of a subordinate query.

     

    You imbed the subordinate query in the WHERE clause using the Criteria page.

    Step 1
  2. Note these points about subqueries:

    •   The condition type that you specify in the criteria determines what the subquery returns to the query.

    •   A subquery can retrieve only one data field from a single table, and the subquery can contain a join.

    •   The result of the subquery itself is never displayed; the results of the query are displayed, and they are limited by the subquery.

    •   Additional rows of criteria can be placed in the primary query or the subquery.

    Step 2
  3. This diagram shows the process of creating a single-value subquery.

    Step 3
  4. You can use every page in Query Manager, except the Run page, to navigate between the top-level query and the subquery.

    Step 4
  5. After you create a subquery, you might need to navigate from the primary query to the subquery and then back to the primary query.

     

    For example, you might need to:

    •   Insert additional criteria in the primary query.

    •   Modify the primary query or the subquery.

     

    If so, you use the Subquery/Union Navigation link on the Fields page to navigate between primary query and subquery.

    Step 5

You have successfully reviewed the Understanding Subqueries topic.

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