AnyDAC (FireDAC) - Open transaction after TBlobField.GetAsString

Question

at the moment we are migrating the database component of our Delphi7 application from the BDE components to the AnyDAC (FireDAC) Version 8.0.5 components.

The following prerequisites are given:

• On our form we have one TADConnection, one TADQuery and one TADTable. The TADQuery is the MasterSource for the TADTable. No special changes have been made to the settings of the AnyDAC components, so the AutoCommit mode is active.
• Furhtermore we have one TDBMemo on our form which is linked to an ftMemo field of the TADTable (Firebird FieldType = Blob / Size = 240 / Subtype = Text)

During the loading of the blob text field content (TBlobField.GetAsString) the TADTable starts automatically an transaction which would not committed.

Is this behavior normal? Do we have any possiblity to avoid this open transaction? Please note, deactivating of the AutoCommit is no option at the moment.

Any help appreciated.

Answer 1

Yes, that is a normal behavior. So long you are not fetching BLOB data along with the detail tuple, AnyDAC starts an implicit transaction for fetching those BLOB data.