IBO native dataset architecture does it but the limitation you are experiencing is due to the TDataset architecture provided by Embarcadero.

You might need to have a little routine that plugs into the OnSetText event of each TStringField and to have it raise the exception when needed.

Jason

Found the property but it does not seem to work for IBO components, i.e. I switched it off on the TIBODatabase and an update with a TIBOQuery does not raise any exception when the string is too long. If this is indeed a limitation of IBO, could you possibly resolve it please?