FreeTDS Development Group

[Frediano Ziglio <freddyz77 AT tin.it>]

Il giorno ven, 10/03/2006 alle 19.49 -0800, John Wythe (work) ha
scritto:
> I have found a problem with SQLExecDirect.  If I execute a query that is 
> not intended to return data, I get an SQL_NO_DATA result.  This is not what 
> the same function returns on Windows, it returns SQL_SUCCESS.   If I use 
> ISQL to execute the query, which uses SQLPrepare, and SQLExecute, I get the 
> proper result.
> 

This is not a problem... ODBC 3 specification document that
SQLExecDirect should return SQL_NO_DATA if no data returned... mssql
driver seems to not complain to these specifications... I'll look more
deeper...

Can you post a query that cause this behavior?


> I have looked at the source, and found the problem.  Maybe you can look at 
> the before and after code snippets and tell me if I made the right change, 
> or direct me how to make the correct change.   Eventually the fix should 
> probably be incorperated into the main code.   Basically, from debugging 
> the program, the done flag doesn't get set, and the program tries to get 
> another token, but there aren't any more, so it thinks it was trying to do 
> a SQLFetch for more data which in that case should return SQL_NO_DATA, 
> since, in this case in_row is zero, this is not the case. My question would 
> be whether or not TDS_DONEPROC_RESULT should also do this?
> 
> Snippets from src/odbc/odbc.c    function SQLExecDirect
> 
> Before:
>         case TDS_PARAM_RESULT:
>             odbc_set_return_params(stmt);
>             break;
> 
>         case TDS_DONE_RESULT:
>         case TDS_DONEPROC_RESULT:
>             if (done_flags & TDS_DONE_COUNT) {
>                 got_rows = 1;
> After:
> 
>         case TDS_PARAM_RESULT:
>             odbc_set_return_params(stmt);
>             break;
> 
>         case TDS_DONE_RESULT:
>             if (!in_row && !(done_flags & TDS_DONE_COUNT) && !(done_flags & 
> TDS_DONE_ERROR))
>         /* prevent queries with no result set from returning SQL_NO_DATA 
> jww */
>                 stmt->row_count = 0;
>             else {
>                 if (done_flags & TDS_DONE_COUNT) {
>                     got_rows = 1;
>                     stmt->row_count = tds->rows_affected;
>                 }
>                 if (done_flags & TDS_DONE_ERROR)
>                     stmt->errs.lastrc = SQL_ERROR;
>             }
>             done = 1;
>             break;

Quite complicated... where does this code came?

>         case TDS_DONEPROC_RESULT:
>             if (done_flags & TDS_DONE_COUNT) {
>                 got_rows = 1;
> 
> Thanks
> 
> John

freddy77