Lately I created an Oracle 8.04 CLOB field and a TOracleDataSet which accessed the corresponding table.

I also created a persistent datafield which shows its type as TMemoField and its property BlobType as ftOraClob.

On command OracleDataSet1.Open an AV occurred: "Unexpected datatype.". I changed property BlobType to ftMemo but the same result.

I never had this problem before and now don't know what to do. Any advice would be helpful.

Thanks in advance.

TMemoField and ftOraClob are correct for a CLOB field. Can you activate the dataset at design time?

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Marco Kalter
Allround Automations

It's a little bit strange. A long as the CLOB field is empty, connection and read/write is possible and even writing the first input to the CLOB works fine.

But on the next table activation the AV occurs. This happens in my EXE and at design time.

If I clear the field again with SQLPlus then the AV doesn't appear any more.

By the way. Perhaps it may be a problem of different Oracle client and server versions as described in another of my requests (TNSNAMES.ORA)?!

When you say AV, do you really mean an Access Violation? I assumed that you got an "Unexpected datatype" exception.

If it is an Access Violation, what is the module and address?

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Marco Kalter
Allround Automations

I apologize for the wrong abbreviation. It is in fact an "unexpected datatype" exception, no AV.

I'm afraid you need to do some more debugging, because I can't think of an obvious explanation for this problem. When exactly does the exception occur?

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Marco Kalter
Allround Automations

Indeed I did some more research and the conclusion is that in fact it seems to be an Oracle version problem.

After I connect from the 8.17 client to the 8.17 server the exception does not occur any more. I can edit and save the CLOB field.

If I connect to the 8.04 server again the exception occurs again.