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Q129634: Jet DB Engines Process ‘Data Has Changed’ Error Differently

Article: Q129634
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0
Operating System(s): 
Keyword(s): kbcode
Last Modified: 02-NOV-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SUMMARY
=======

The Microsoft Jet version 1.1 database engine behaves differently from the
version 2.0 and 3.0 database engines when it comes to processing the 'Data Has
Changed' error message.

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

The Microsoft Jet version 1.1 database engine shipped with Visual Basic version
3.0. The Microsoft Jet version 2.0 database engine shipped with Microsoft Access
version 2.0, and the The Microsoft Jet version 3.0 database engine shipped with
Visual Basic version 4.0.

In Jet 1.1, the error is triggered, by default, to warn the user whenever data is
changed in the table. However, in Jet 2.0 and 3.0 this error is not
automatically triggered when data changes. To cause the Jet 2.0 and 3.0 database
engines to trigger the error message, you need to set the Options property for
the recordset to dbSeeChanges (512).

Examples Using Visual Basic Version 4.0 Syntax
----------------------------------------------

To change the Options property on a data control to the proper value, use one of
the following two methods:

- In the design environment, make sure that the data control is the selected
  item on your form. Then go to the properties sheet, and set the Options
  property to 512.

-or-

- In the runtime environment, use the following line of code to set the Options
  property of a data control named data1:

      data1.options = dbSeeChanges

To create a recordset with the Options property set to dbSeeChanges, you can use
this code segment:

     Dim db As Database
     Dim rs As Recordset

     Set db = DBEngine.WorkSpaces(0).OpenDatabase("biblio.mdb")
     Set rs = db.OpenRecordset("authors", dbOpenDynaset, dbSeeChanges)

Steps to Trigger Error
----------------------

After the Options property of the recordset is set, you can trigger the error by
performing the following sequence of events:

1. Ensure that two programs have the same record open in an edit mode.

2. Have both programs make changes to that record.

3. Have one program save its changes.

4. Have the second program attempt to save its changes. At this point, the error
  message is triggered.

Additional query words: 4.00 vb4win vb4all

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Keywords          : kbcode 
Technology        : kbVBSearch kbAudDeveloper kbVB400Search kbVB400 kbVB16bitSearch
Version           : :4.0

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