FreeTDS Development Group

["Thompson, Bill D (London)" <bill_d_thompson AT ml.com>]

James,

> dbresults() behaves that way because tds_process_result_tokens()
returns
> SUCCEED rather than NO_MORE_RESULTS after it finds the PRINT output.
> Each function blithely returns the called function's return code, and
> none is willing to say, hey buddy, there're no more results.  

Actually, that didn't turn out to be the issue.
I wrote a bare-bones dblibrary program, which I could then compile using
Sybase open-client & freetds.
Here's the bare bones of the program:

result_code = dbcmd(dbproc, "select 1 print 'hi'");
printf("dbcmd result_code = %d\n", result_code);
result_code = dbsqlsend(dbproc);
printf("dbsqlsend result_code = %d\n", result_code);
result_code = dbsqlok(dbproc);
printf("dbsqlok result_code = %d\n", result_code);

while ((result_code = dbresults(dbproc)) == SUCCEED) {
    printf("dbresults result_code = %d\n", result_code);
    num_cols = dbnumcols(dbproc);
    printf("number of columns = %d\n", num_cols);
    if ( dbrows(dbproc) == SUCCEED) {
        printf("there are rows to process\n");
        while ((result_code = dbnextrow(dbproc)) != NO_MORE_ROWS) {
             printf("dbnextrow result_code = %d\n", result_code);
        }
        printf("dbnextrow result_code = %d\n", result_code);     
    }
}
printf("dbresults result_code = %d\n", result_code);

This yielded the following output, using Sybase open-client:

dbcmd result_code = 1
dbsqlsend result_code = 1
dbsqlok result_code = 1
dbresults result_code = 1
number of columns = 1
there are rows to process
dbnextrow result_code = -1
dbnextrow result_code = -2
Msg 0, Level 0, State 1
Server 'MYSERVER', Line 1
        hi
dbresults result_code = 1    <= NOTICE THIS SUCCEED return 
                             after the "print" is processed
number of columns = 0
dbresults result_code = 2

The REAL problem was our (very) old friend of "when to free/initialise
the results structure".
Basically, we are not freeing the res_info data at the correct time. It
hangs around until another results token is read.
Fortunately the new, more "state-driven", dbresults processing allows us
to work out much more easily when it is pertinent to free the results
structures.

I've worked out a patch for this, and our dblibrary behaviour now mimics
Sybase open client.
What's more, all dblibrary unit tests still work (phew!)

I think I'll wait though until after the holidays before giving you the
patch.

Happy Holidays everyone,

Bill 
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