PRB: SET INDEX TO Command Causes Error When Run from a Form (140565)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
  • Microsoft Visual FoxPro for Windows 3.0b
This article was previously published under Q140565

SYMPTOMS

One of the following errors occurs occur when attempting to run the SET INDEX TO command programmatically from a running form:

  • File must be opened exclusively. -or-

  • File is in use by another.

CAUSE

A table opened by the Data Environment of a form is opened shared by default. Therefore, when the form is running and you issue an INDEX ON command, an error occurs.

RESOLUTION

Set the Exclusive Property of the cursor to .T. at design time.

NOTE: Attempting to set this property at run-time causes the following error message:
Property setting will not take effect until data environment reloaded

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a form.
  2. Right-click the form, and then click Data Environment.
  3. Right-click the Data Environment window, and then click Add.
  4. Locate the Customer table in the Vfp\Samples\Data directory, and then select and add it to the Data Environment of the form.
  5. Scroll down in the list box displaying the Customer table and note which indexes which currently exist. This is so that an index that already exists isn't recreated when the INDEX ON command is run in Step 7 later.
  6. Add a command button to the form.
  7. Add the following code to the Click method of the command button 
         SELECT CUSTOMER
     INDEX ON <field_name> TAG <field_name>
    where field_name is the name of a field in the Customer table that does not already have an index tag, as noted earlier in Step 5.
  8. Save and run the form.
  9. Click the command button.

Steps to Correct Form Created in Previous Example

  1. Close, and then edit the form.
  2. Right-click the form, and then click Data Environment.
  3. Right-click the Customer table list box, and then click Properties.
  4. In the Properties window, click the Data tab, and then examine the Exclusive property. Note that the default value is .F.
  5. Change the Exclusive value to .T., and then save and rerun the form.
Modification Type:MajorLast Reviewed:9/30/2003
Keywords:kberrmsg KB140565
©2003 Microsoft Corporation. All rights reserved.