Check for duplicates before post

[Valgardur]

Trying to detect posting of a duplicate key and presenting an application friendly error message I am running into problems..

I found two forum messages, one saying in OnPostErorr do something like ..

if (E is EMSError) and (EMSError(E).ErrorCode = ...) then ...

which is not of much help.

The other suggesting a bookmark and locate (which results in access violation error).

As far as I can tell, OnPostError only gets called after default message is displayed.. and with absolutely no information.

There is nothing on OnPostError in SDAC documentation.

[azyk]

You can handle this error ( http://www.microsoft.com/products/ee/tr ... EvtID=2627 ) by the error code in a TMSQuery.OnPostError event handler using EMSError exceptions. The error code value is stored in the EMSError.MSSQLErrorCode property. For example:

Code: Select all

procedure TMainForm.MSQuery1PostError(DataSet: TDataSet; E: EDatabaseError;
  var Action: TDataAction);
begin
  // Violation of %ls constraint '%.*ls'. Cannot insert duplicate key in object '%.*ls'.   
  // (Microsoft SQL Server, Error: 2627)
  if (E is EMSError) and (EMSError(E).MSSQLErrorCode = 2627) then
  // DoSomething;
  ...
end;

See more details about OnPostError event handler in the Embarcadero documentation: http://docwiki.embarcadero.com/Librarie ... nPostError .

[Valgardur]

1) As explained.. the error is displayed before OnPostError
2) Where do I find the error codes?
3) Where can I find documentation?

[azyk]

Please try to compose a small sample reproducing the described behavior and send it to andreyz*devart*com . Include scripts for creating the test tables into the sample.

[Valgardur]

I actually could not possibly wait the 10 days since I posted this.. so I already found a different approach, although I had to waste more time than acceptable. And to be honest, with the response time here it seems a waste of time to produce an example..

It would though, be helpful to know where to find those codes and where I can find documentation.

[azyk]

You can find description of error codes generated by SQL Server in the MSDN documentation:
https://technet.microsoft.com/en-us/lib ... .105).aspx .