FreeTDS Development Group

[brian AT bruns.com]

Does it happen with non-ODBC applications?  That is if
you run it with sqsh, can you reproduce it there as
well?

This would help us narrow down the cause.

Brian

On Thu, 08 Jan 2004 16:17:57 -0500, Steven Orton wrote:

> 
> so far its occured with any client that uses the
> freeTDS driver and sends SQL
> commands.  So it happens using my client and
OpenLink's
> odbctest application. 
> I can't see anything in my dump logfile that indicates
> an error condition (no
> explicit ERROR indicater).  It just hangs with the
> output log indicating it
> sent the out packet and where it normally dumps the
> reply packet, there is
> nothing.  Is there any other "thing" I can use to see
> anything else?
> 
>   steve---
> 
> 
> 
> brian AT bruns.com wrote:
> 
> > All this misses the point of course, which is that
> > FreeTDS is oblivious to using DISTINCT or any other
> SQL
> > construct.  All it care about are the number and
types
> > of columns/rows coming back.  This problem if it
lies
> > within FreeTDS should be reproducible with the
simple
> > "SELECT * from table1 where Target_ID=:C" (:C being
> > some constant normally returned from the subquery.
> > 
> > Perhaps some action within the application has left
> the
> > TDS connection in a bizarre state.  See if you can
get
> > this to reproduce on a smaller scale maybe? (that
is,
> > cut the code down to the barest essentials while
> having
> > it still fail).
> > 
> > Brian
> > 
> > On Thu, 08 Jan 2004 11:18:42 -0800, Michael Peppler
> > wrote:
> > 
> > > 
> > > On Thu, 2004-01-08 at 11:08, Lowden, James K
wrote:
> > > > > From: Steven Orton [mailto:sorton9999 AT usa.net]
> > > > > Sent: January 8, 2004 1:57 PM
> > > > > 
> > > > >   I seem to be having problems with the
> following
> > > query:
> > > > > 
> > > > >   SELECT * FROM table1 WHERE Target_ID=(SELECT
> > > DISTINCT 
> > > > > Target_ID FROM table2
> > > > > WHERE PlatformTypeID=62 AND db_ctx_id=3)
> > > > 
> > > > It's not a good idea to rely on a subquery
> returning
> > > only one row to a point
> > > > evaluation.  How do you expect the server to
cope
> if
> > > it returns two
> > > > (distinct) Target_IDs?  
> > > > 
> > > > I would do:
> > > > 
> > > > SELECT * FROM table1 
> > > > WHERE Target_ID in (
> > > >         SELECT DISTINCT Target_ID 
> > > >         FROM table2
> > > >         WHERE PlatformTypeID=62 
> > > >         AND db_ctx_id=3
> > > >         )
> > > 
> > > In general using a join rather than a sub-query
gets
> > > better performance:
> > > 
> > > select * 
> > >   from table1 t1
> > >      , table2 t2
> > >  where t1.TargetID = t2.TargetID
> > >    and t2.PlatformTypeID = 62
> > >    and t2.db_ctx_id = 3
> > > 
> > > Michael
> > > -- 
> > > Michael Peppler                              Data
> > > Migrations, Inc.
> > > mpeppler AT peppler.org                
> > > http://www.mbay.net/~mpeppler
> > > Sybase T-SQL/OpenClient/OpenServer/C/Perl
developer
> > > available for short or 
> > > long term contract positions -
> > > http://www.mbay.net/~mpeppler/resume.html
> > > _______________________________________________
> > > FreeTDS mailing list
> > > FreeTDS AT lists.ibiblio.org
> > > http://lists.ibiblio.org/mailman/listinfo/freetds
> > _______________________________________________
> > FreeTDS mailing list
> > FreeTDS AT lists.ibiblio.org
> > http://lists.ibiblio.org/mailman/listinfo/freetds
> > 
> 
> 
> 
> -------------------------------
> Steven Orton
> sorton9999 AT usa.net
> --
> "Put your hand on a hot stove for a minute,
>  and it seems like an hour.
>  Sit with a pretty girl for an hour, and it
>  seems like a minute. THAT'S relativity."
>         -- Albert Einstein
> -------------------------------
> 
> 
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