Blob will not set to NULL

Discussion of open issues, suggestions and bugs regarding SDAC (SQL Server Data Access Components) for Delphi, C++Builder, Lazarus (and FPC)
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fis_pelzer
Posts: 1
Joined: Wed 03 Sep 2008 07:46

Blob will not set to NULL

Post by fis_pelzer » Wed 03 Sep 2008 07:55

Hi,

we use Delphi 7 and the SDAC Version 4.50.
We create a wrapper class the connect with the Database and this class has the property query with is a TMSQuery.
We

We use this code snippet to set a blob field to null

Code: Select all

tdataset(tmsquery).FieldByName("db_field_image_blob").SetData(nil);
And after that we do POST to the query.

With the ADO implementation of Delphi is works fine, but with the SDAC component the NULL value wouldn't set to the database.

Have enyone an idea, were the problem can be?

CU
Sven

Dimon
Devart Team
Posts: 2885
Joined: Mon 05 Mar 2007 16:32

Post by Dimon » Thu 04 Sep 2008 11:52

To set the NULL value in the Blob field, you should call the Clear method, like this:

Code: Select all

tmsquery.FieldByName("db_field_image_blob").Clear;

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