Bryan Pendleton <[EMAIL PROTECTED]> writes:
>> Long story short someone who works with the client pointed out that
>> the client is sending a QRYROWSET of size "0" when it sends the
>> OPNQRY
>
> Hi Army,
>
> Page 698 of V.3 says:
>
> A QRYROWSET value of zero on the OPNQRY and EXCSQLSTT commands instructs
> the server to return no rows with the OPNQRYRM for the cursor or result
> set. A QRYROWSET value of zero on the CNTQRY command is invalid for
> non-rowset cursors and results in the application server generating a
> SYNTAXRM with a SYNERRCD value of '15'x (reserved value not allowed).
>
> I'd say that our current behavior, as you describe it, seems wrong; we should
> not be returning any rows when the client has set QRYROWSET to 0 on OPNQRY.
>
> I think that we should modify the server code for 10.2 so that:
>
> - on OPNQRY and EXCSQLSTT, we only return rows if QRYROWSET is > 0.
... or if (QRYPRCTYP == LMTBLKPRC && QRYROWSET is not set).
> - on CNTQRY, we throw a syntax exception if QRYROWSET is 0
>
> I'm quite interested to hear what others think about this.
I agree that the current behaviour is wrong and that it should be
changed as you describe. I don't have the DB2 ODBC driver, but I ran a
couple of tests with the client driver, and this is what it does on
OPNQRY:
Forward-only/read-only:
- no QRYROWSET is sent
- QRYPRCTYP = LMTBLKPRC
- up to 32 KB of data is pre-fetched
Forward-only/updatable:
- no QRYROWSET is sent
- QRYPRCTYP = FIXROWPRC
- doesn't pre-fetch data
Scrollable/read-only:
- QRYROWSET = 64
- QRYPRCTYP = LMTBLKPRC
- min(32 KB, 64 rows) is pre-fetched
Scrollable/updatable:
- QRYROWSET = 64
- QRYPRCTYP = FIXROWPRC
- no pre-fetching
Since the client never sends QRYROWSET=0 on OPNQRY, I don't think the
client will have this problem.
When I look at writeQRYDTA and writeFDODTA in DRDAConnThread, it seems
to me that we actually break the DRDA spec in two ways:
1) QRYROWSET=0 has the same effect as QRYROWSET=1
2) For forward-only/read-only result sets, QRYROWSET will be ignored
(both on OPNQRY and CNTQRY) - haven't verified this since the
client doesn't send QRYROWSET in this case.
1 is causing the reported problem with the ODBC driver. I don't know
if 2 is a problem. The client driver never sends an explicit QRYROWSET
when the result set is forward-only, but maybe the ODBC driver does.
--
Knut Anders
