QUERY BY EXAMPLE

version 3

QUERY BY EXAMPLE ({aTable}{; }{*})

QUERY BY EXAMPLE performs the same action as the Query by Example menu command in the Design environment. It displays the current input form as a query window. QUERY BY EXAMPLE queries aTable for the data that the user enters into the query window. The form must contain the fields that you want the user to be able to query. The query is optimized; indexed fields are automatically used to optimize the query.

See the 4D Design Reference manual for information about using the Query by Example menu command in the Design environment.

The method in this example displays the MyQuery form to the user. If the user accepts the form and performs the query (that is, if the OK system variable is set to 1), the records that meet the query criteria are displayed:

   INPUT FORM ([People]; "MyQuery")  ` Switch to query form
   QUERY BY EXAMPLE ([People])  ` Display form and perform query 
   If (OK=1)  ` If the user performed the query 
      DISPLAY SELECTION ([People])  ` Display the records
   End if

ORDER BY, QUERY.

If the user clicks the Accept button or presses the Enter key, the OK system variable is set to 1 and the query is performed. If the user clicks the Cancel button or presses the "cancel" key combination, the OK system variable is set to 0 and the query is canceled.