11/14/1995

{ PURPOSE: The purpose of this code fragment is to demonstrate the use of a call to the BDE
           function DbiQExecDirect to avoid having the SQL statement parsed for parameters
           (i.e. anything preceded by a colon)

           In this case, it is being used to create an Oracle trigger, where :new refers to
           the new version of the updated record.  Conversely, :old refers to the record
           before the update.  Oracle also happens to use := as an assignment operator in
           triggers.
}


uses
  ..., DbiProcs, DbiTypes;


procedure TForm1.Button1Click(Sender: TObject);
var
   { We need a pchar, but the following declaration amounts to the same thing and saves 
     us from having to explicitly allocate/deallocate the memory for it.
   }
   SQLString : array[0..255] of char;

begin

   { Get database handle required by DbiQExecDirect. }
   Database1.open;

   { Convert SQL statement from Pascal string to null-terminated string. }
   StrPCopy(SQLString, 'CREATE OR REPLACE TRIGGER ab_update BEFORE UPDATE OF B ON swu.ab FOR EACH ROW BEGIN :new.B := :new.A; END;');

   { Parameters:
        First parameter is the database handle,
        Second is the query type (qryLangSQL or qryLangQBE),
        Third is the null-terminated query string,
        Fourth is the handle to the result set (in this case there is none so we can pass nil)
   }
   DbiQExecDirect(Database1.Handle, qryLangSQL, SQLString, nil);

end;

end.


SWU

ID:CSxxxx