Question

I have this Firebird stored procedure:

SET TERM ^ ;
CREATE PROCEDURE MYSP ( FIRSTPARAM Varchar(3) )
    RETURNS ( ERROR Varchar(128) )
AS BEGIN
    /* a lot of things, including setting a value to ERROR */
    suspend;
END^
SET TERM ; ^

I need to execute this procedure in C++ Builder XE2 and finally read its return value (ERROR) to see if it succeded. Procedure returns only one row.

I tried this way:

TIBQuery* q = DMH->ordQuery;
q->Close( );
q->SQL->Clear( );
q->SQL->Text = "EXECUTE PROCEDURE MYSP(:P1)";

if ( !DMH->ordTrans->InTransaction )
{
    MakeCommit = true;
    DMH->ordTrans->StartTransaction( );
}
if ( !q->Prepared )
    q->Prepare( );

q->Params->ParamByName( "P1" )->Value = "abc";
q->Open();

//success if error field contains NULL
TField* errorField = q->FieldByName( "ERROR" );
bool success = errorField->IsNull;

if ( MakeCommit )
    DMH->ordTrans->Commit( );

It gives me an access violation on errorField, because it can’t find such field.

Answer 1

I had to change the statement:

SELECT ERROR
FROM MYSP(:P1)