Get error message or exception using ExecuteDirect (Zeos components)
lazarus / 16-Databases

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derles · 2013-07-11 16:32

Hello.

I´m using Lazarus and Firebird, with Zeos components.

When I needed to execute an INSERT, UPDATE  or DELETE sentence, I
usually used a ZQuery component, with the ExecSQL method.
As in this code portion:   (sQ variable contains mi SQL sentence).

try
     zQuery01.SQL.Text:= sQ;
     zQuery01.ExecSQL;
     Result := True;
except
     on E:Exception do
     begin
         Result := False;
         ShowMessage('An error occurs: '+E.Message);
     end;
end;

Now I'm trying to use ZConnection.ExecuteDirect instead
ZQuery.ExecSQL. It looks simplier.
But the problem I find is this: when the sql sentence was not
succesful (syntax error, or PK duplicates o something else), I don't
know how to capture the error to show the error message.
I mean: the ExecuteDirect returns False, but I think no exception is
thrown. Is this correct? So, where can I find the error message
returned? is this possible?

Thanks.

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garlar27 · 2013-07-11 17:17

ExecuteDirect is way much faster than ExecSQL. And yes, it don't tell
you what error happened.

what I do is this:
Code: [Select]if not zConnection.ExecuteDirect(sQ) then
   try
        zQuery01.SQL.Add(sQ);// <---   THIS IS FASTER THAN
zQuery01.SQL.Text:= sQ;
        zQuery01.ExecSQL;
        Result := True;
   except
        on E:Exception do
        begin
            Result := False;
            ShowMessage('An error occurs: '+E.Message);
        end;
   end;

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derles · 2013-07-11 18:37

I see.
Ok garlar, I probably adopt your code in my function. 

Thank you.

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garlar27 · 2013-07-11 20:08

Quote from: derles on July 11, 2013, 08:37:04 pmI see.
Ok garlar, I probably adopt your code in my function. 

Thank you.

Although it would be nice to know if there is a better solution...