ODBC-update problem with Jet-Engine and null values

My problem again, but now more specific:

I get the error message 'data changed by another user' (visual basic-error 3197) when I try to update or delete a row in oracle tables (primary key exists, all columns are character-type) with the .update or .delete method in vb4 (16-bit) or directly in a linked access (2.0 / 97) table .

After searching a long time for the reason, now I have detected following reason:

In the ODBC-trace file I detected, that the Jet-Engine makes the update / delete with a where clause, where all columns are listed, although the engine knows the primaery key !!!

"UPDATE TEST1.T_STATUS SET F1=? WHERE F2 = ? AND F1 = ? AND F3 = ?" Also I recognized, that this statement do not work, when the Parameter (?) is Null. And this is my problem !!! The server answers correctly "no data found", but the jet-engine thinks "data are changed by another user".

But can this be true ?! There must be a trick - its a joke, isnt it ?

Sure, I can use directly my own SQL-Statements, but I have to migrate an existing big program and don´t like to change to much.

Any idea / help ? This would be great !!!!

I use ORACLE 8.0.3.0.0 on NT Server 4.0 (SP3), TCP/IP, and Client NT 4.0 (SP3) with Access 2.0 / 97 / Visual Basic 4.0 *(16-Bit) with ODBC 8.0.3.0.0 32-Bit. Received on Tue Mar 10 1998 - 00:00:00 CST