Jet DB Engines Process 'Data Has Changed' Error Differently

• Professional and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0
• Microsoft Jet 3.0/Visual Basic 4.0 Compatibility Layer

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
  

   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.