Microsoft KB Archive/209146

= ACC2000: List Box Column Property Receives Incorrect Row Information =

Article ID: 209146

Article Last Modified on 6/24/2004

-

APPLIES TO


 * Microsoft Access 2000 Standard Edition

-



This article was previously published under Q209146



Moderate: Requires basic macro, coding, and interoperability skills.

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



SYMPTOMS
When you select a row from a multicolumn list box or combo box, controls that reference the Column property of the list box or combo box retrieve data from a different row in the list box or combo box.

NOTE: A list box may appear to work as expected, but when you bind the list box, it exhibits the same behavior as a combo box.



CAUSE
This behavior occurs because the list box or combo box's BoundColumn property does not point to a field with unique values.



RESOLUTION
The list box or combo box's BoundColumn property must point to a field that contains unique values. If the BoundColumn property does not point to a field with unique values, Microsoft Access returns information for the first row with a matching BoundColumn value when you select a row in the list box or combo box.

For example, the Type field in the sample table below does not contain unique values. If the Type field is used for the BoundColumn property, a text box referencing the second column returns "Apple" rather than "Grape" when you select the third row.

Type   Description --- Fruit  Apple Fruit  Orange Fruit  Grape If you use the Description column for the BoundColumn property, this behavior does not occur because the Description column contains unique values.

Another way to resolve this behavior is to add an AutoNumber field to the underlying table, and then use the AutoNumber field for the BoundColumn property.

You can also use the ListIndex property of the combo box or list box to reference the selected row in the combo box or list box. Microsoft Access sets the ListIndex property value when an item is selected in a list box or list box portion of a combo box. The ListIndex property value of the first item in a list is 0, the value of the second item is 1, and so on. The code below refers to the example listed in the "More Information" section of this article. You can add this code to the AfterUpdate property of the combo box: Private Sub Manufacturer_AfterUpdate Me![Stock Number] = Me![Manufacturer].Column(1, Me![Manufacturer].ListIndex) Me![Description] = Me![Manufacturer].Column(2, Me![Manufacturer].ListIndex) End Sub NOTE: If you use this code, remove the expressions that are assigned to the ControlSource properties of the Stock Number and Description controls.

Note that the ListIndex property value can be accessed indirectly by setting the BoundColumn property of a combo box or a list box to 0. If the BoundColumn property is set to 0, the underlying table field to which the combo box or list box is bound contains the same value as the ListIndex property setting.



Steps to Reproduce Behavior
 If you are working with Microsoft Access database, create the following table:

Table: Table1

Field Name: Manufacturer

Data Type: Text

Field Name: Stock Number

Data Type: Number

Field Size: Long Integer

Indexed: Yes

Field Name: Description

Data Type: Text

Table1 Properties:

Primary Key: Stock Number

If you are working with Microsoft Access project, create the following table:

Table: Table1

Field Name: Manufacturer

Data Type: Text

Field Name: Stock Number

Data Type: Int

Allow Nulls: No

Field Name: Description

Date Type: Text

Table1 Properties:

Primary Key: Stock Number

  View the table in Datasheet view. Add the following data to the table: Manufacturer  Stock Number   Description - IB Co         1              Mouse IB Co         2              Printer IB Co         3              Hard Drive ComCo         4              PC                     Create the following new form:

Form: Test1

Combo box:

Name: Manufacturer

ControlSource:

RowSourceType: Table/Query

RowSource: Table1

ColumnCount: 3

BoundColumn: 1

Width: 3

Text box:

Name: Stock Number

ControlSource: =[Manufacturer].Column(1)

Text box:

Name: Description

ControlSource: =[Manufacturer].Column(2)

 View the form in Form view.</li> Select the first row in the combo box.

Note that the Stock Number and Description boxes correctly display "1" and "Mouse."</li> Select the third row in the combo box.

Note that the Stock Number and Description boxes still display the information from the first row.</li> Select the fourth row in the combo box.

Note that the Stock Number and Description boxes display the correct information for the fourth row.</li></ol>

If you change the BoundColumn property of the Manufacturer list box to 2 instead of 1, the text boxes on the form display the correct information for all the rows in the list box because the second column contains unique values.

<div class="references_section">