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Q139348: HOWTO: Set a Filter Using an Item Selected from a Combo Box

Article: Q139348
Product(s): Microsoft FoxPro
Version(s): 
Operating System(s): 
Keyword(s): kbnokeyword kbvfp300 kbvfp500 kbvfp600
Last Modified: 03-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 6.0 
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SUMMARY
=======

This article shows by example how to use the item selected in a combo box to
filter what is displayed in a second combo box.

MORE INFORMATION
================

The Scenario
------------

Say you have two combo boxes on a form. The first reflects a field in the parent
table, and the second reflects the child records related to the parent value
picked from the possible parent values presented in the first combo box.

Step-by-Step Procedure
----------------------

1. Create a new form.

2. Right-click the form, and click Data Environment. Then right-click the Data
  Environment window, and add the Customer table from \Vfp\Samples\Data. In
  Visual FoxPro 6.0 the Customer table can be found in home(2)+"data".

3. Right-click the Data Environment window again, and add the Orders table from
  \Vfp\Samples\Data. In Visual FoxPro 6.0 the Orders table can be found in
  home(2)+"data".

4. Place a combo box on the form. Change its RowSource property to
  Customer.cust_id and its RowSourceType property to 6 - Fields.

5. Add the following code to the InteractiveChange event for the combo box:

  

     thisform.dataenvironment.cursor2.filter= ;
        "alltrim(cust_id)='"+alltrim(this.value)+"'"

6. Place a second combo box on the form. Change its RowSource property to
  Orders.to_name and its RowSourceType property to 6 - Fields.

7. Save and run the form.

8. Select a customer ID from the first combo box. Click the down arrow on the
  second combo box, and note the records displayed in the second combo box
  relates to the customer ID you selected from the first combo box.

NOTE: If you place the line of code in Step 5 in the Valid event for the combo
box, the event fires twice - once when you select an item from the combo box and
again when the combo box loses the focus. Placing the code in the
InteractiveChange event avoids this behavior.

Additional query words:

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Keywords          : kbnokeyword kbvfp300 kbvfp500 kbvfp600 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP500 kbVFP600
Issue type        : kbhowto

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