FIX: dBASE & FoxPro Memos Corrupted During Concurrent Addnew

The information in this article applies to:

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, version 3.0

SYMPTOMS

When two or more programs concurrently edit and/or add new records to the same dBASE or FoxPro table and that table contains a memo field, the memo field can become corrupted.

CAUSE

This is not a bug Visual Basic itself, but a bug in the Microsoft Jet Database Engine used by Visual Basic.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem has been corrected in Visual Basic version 4.0.

MORE INFORMATION

This problem arises when two or more Edit or Addnew operations are pending on the same table at the same time. When the record is updated, whichever program updates the memo field last has its memo data written into the memo field of the previously updated record.

Steps to Reproduce Problem

To duplicate this problem, you must already have a dBASE or FoxPro table that has a memo field in it.

1. From Visual Basic's Window menu, choose the Data Manager (ALT, W, A).

2. Restore the Data Manager's window to normal by clicking the Restore/Max button (ALT, SPACE, R).

3. Open a dBASE or FoxPro database that contains a table with a memo field (ALT, F, O).

4. Select the table from the Tables list, and choose Open.

5. Repeat steps 1 through 4 to provide a second instance of the Data Manager editing your table.

6. For the first instance, add a new record and edit the data in the memo field to say Instance1.

7. For the second instance, add a new record and edit the data in the memo field to say Instance2.

8. Choose Update and Save the Changes for the first instance. Repeat for the second.

9. Choose Refresh to update the recordset. When you view the records, you'll see that the memo fields in both instances read Instance2.