FreeTDS Development Group

[Frediano Ziglio <freddyz77 AT tin.it>]

Il gio, 2004-02-12 alle 22:28, Matthew A. Davis ha scritto:
> When I send an UPDATE using SQLExecDirect(), then check the number of 
> affected rows, all is fine.  When I send the same command using 
> SQLPrepare() and SQLExecute(), checking the number of effected rows fails 
> with SQLState 24000 (Invalid Cursor).
> 
> I've made my test code available on the web: 
> http://www.speakeasy.org/~azami/code/
> In addition to the .cpp file, I've included tdsdump logs for the two cases.
> 
> Basically, after connecting and getting a statement, I'm doing this:
> 
> SQLPrepare(hstmt, (SQLCHAR *)("UPDATE SQLDEV1.OT_LastRecordID SET RecordID 
> = RecordID + 1"), SQL_NTS);
> SQLExecute(hstmt);
> SQLRowCount(hstmt, &rows);
> 
> In this case SQLRowCount fails.  If I SQLExecDirect() the exact same 
> statement:
> 
> SQLExecDirect(hstmt, (SQLCHAR *)("UPDATE SQLDEV1.OT_LastRecordID SET 
> RecordID = RecordID + 1"), SQL_NTS);
> SQLRowCount(hstmt, &rows);
> 
> then SQLRowCount succeeds and returns the correct number.
> 
> The OT_LastRecordID table has one column, RecordID, which is an integer.  
> It has one record.
> 
> Looking at the freeTDS source, I see that SQLRowCount() returns this error 
> if stmt->dbc->current_statement != stmt.  I've verified that this is what's 
> happening by returning more info with the error.  current_statement is NULL.
> 
> _SQLExecute() sets current_statement in the middle (odbc.c line 2379), then 
> if tds_process_result_tokens() returns TDS_NO_MORE_RESULTS, it resets 
> current_statement to NULL (line 2441).  It looks like the count is being 
> invalidated when the DONEPROC result token is processed; when we call
> SQLExecDirect, a DONE token is processed instead.
> 
> We are using FreeTDS 0.62.1 on Linux, against SQL Server Personal Edition 
> 8.00.760 (SP3) running on Windows 2000.  The database is set for 
> compatibility level 80.
> 
> Any idea why this is happening?  Is this a bug in FreeTSD, or a problem in 
> our configuration?  I'm quite surprised no one else seems to have 
> encountered this - at least, I wasn't able to find any posts about it 
> through Google or the freetds mailing list archive.
> 

Hi Matthew!
I don't know if SQLRowCount should return error or no_row_count however
you won't be able to read row counts using SQLPrepare and insert. This
behavior reflect wire protocol and it's compatible with Microsoft ODBC.

freddy77