ACC2000: How to Synchronize Two Combo Boxes on a Form

ID: Q209595

The information in this article applies to:
Moderate: Requires basic macro, coding, and interoperability skills.

This article applies to a Microsoft Access database (.mdb) and a Microsoft Access project (.adp).


SUMMARY

This article shows you how to synchronize two combo boxes so that when you make a selection in the first combo box, the selection limits the choices in the second combo box.


MORE INFORMATION

The following example uses the sample database Northwind.mdb. The first combo box lists the available product categories, and the second combo box lists the available products for the category selected in the first combo box:

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  1. Open the sample database Northwind.mdb.


  2. Create a new form not based on any table or query with the following combo boxes, and save the form as Categories And Products. 
    
   Combo Box 1
   -------------------------------
   Name:          Categories
   RowSourceType: Table/Query
   RowSource:     Categories
   ColumnCount:   2
   ColumnWidths:  0";1"
   BoundColumn:   1
   AfterUpdate:   [Event Procedure]

   Combo Box 2
   --------------------------
   Name:          Products
   RowSourceType: Table/Query
   ColumnWidths:  2"
   Width:         2"
    NOTE: If you are in an Access project, the RowSourceType will be Table/View/StoredProc.


  3. Add the following code to the AfterUpdate event procedure of the Categories combo box:


    4. 
Me.Products.RowSource = "SELECT ProductName FROM" & _
   " Products WHERE CategoryID = " & Me.Categories & _
   " ORDER BY ProductName"
Me.Products = Me.Products.ItemData(0)
  4. View the Categories And Products form in Form view. Note that when you select a category in the first combo box, the second combo box is updated to list only the available products for the selected category.


Notes

In the above example, the second combo box is filled with the results of an SQL statement. This SQL statement finds all the products that have a CategoryID that matches the category selected in the first combo box.

Whenever a category is selected in the first combo box, the AfterUpdate property runs the event procedure, which sets the second combo box's RowSource property. This refreshes the list of available products in the second combo box. Without this procedure, the contents of the second combo box would not change.

Additional query words: inf listbox combobox link 


Keywords          : kbdta FmsCmbo 
Version           : WINDOWS:2000
Platform          : WINDOWS 
Issue type        : kbhowto

Last Reviewed: July 6, 1999