Devart Forums

Posted: **Thu 22 May 2008 14:27**

If the database returns an error, I handle it with the OnDeleteError

procedure TFrm.FunctieAanvraagDeleteError(DataSet: TDataSet;
  E: EDatabaseError; var Action: TDataAction);
begin
  Action := daAbort;
  ShowMessage(E.ClassName+' ERROR : '#13#10+E.Message);
end;

As far as I know, there's a EMyError class, witch gives the exact messages and errornumbers of the MySQL database. But why is OnDeleteError using EDatabaseError. Does it give the same results as EMyError?

Posted: **Mon 26 May 2008 14:33**

The EMyError class is inherited from the EDatabaseError class.
In the DeleteError event handler you can cast the E object to the EMyError type and use the ErrorCode and Message values to know the exact message and error number.

Posted: **Tue 27 May 2008 13:49**

This is working

Code: Select all

procedure TPrintOpdrachtenFrm.BtnDeleteClick(Sender: TObject);
begin
   try
   functieaanvraag.Delete;
   except
   on E : EMyError do
   ShowMessage(inttostr(E.ErrorCode) +'; errormessage found : '+EMyError(E).Message);
   end;
end;

But I can't get it to the OnDeleteError event.
Please, can you give me an example to typcast the E to EMyError instaed of using EDatabaseError?

Posted: **Tue 27 May 2008 14:17**

Problem solved.

Code: Select all

EMyError(E)

Posted: **Wed 28 May 2008 10:30**

It is good to see that this problem has been solved.

Devart Forums

OnDeleteError with TMyQuery

OnDeleteError with TMyQuery