FreeTDS Development Group

["ZIGLIO, Frediano, VF-IT" <Frediano.Ziglio AT vodafone.com>]

> 
> My company has successfully used FreeTDS with Apache/PHP to 
> interact with
> our SQL Server 2000 database for several years now.  
> 
> Just today I noticed a problem with a particular stored 
> procedure of ours
> not returning the correct results.  The proper number of 
> records was being
> returned by the routine, but certain fields' values were not 
> correct.  This
> problem only occurs on the newest of our web servers, which 
> is running PHP
> 4.3.9 (on Apache 2) with FreeTDS 0.62.4 installed.
> 
> Upon investigation, it turned out that there was a statement 
> in the stored
> procedure that was calling the COALESCE() function on two 
> database fields,
> both of which could be NULL at the same time (and for a small 
> fraction of
> the records this was exactly the case).  When I called just 
> this SELECT
> query through PHP I received no results - when I modified the 
> COALESCE()
> call to include a third parameter that was guaranteed to be 
> non-NULL, the
> results appeared correctly.
> 
> I should mention that when I run the stored procedure myself directly
> through Query Analyzer, it works fine without modification, i.e. the
> COALESCE() function returns NULL where both parameters are 
> NULL (as the SQL
> Server documentation says it will).  Which brings me to my 
> real point of
> confusion - how can the statements WITHIN the stored 
> procedure be affected
> by the client making the call?  Isn't the stored procedure 
> processed on the
> database server itself?
> 
> I've managed to work around the problem for now by modifying 
> the query, but
> I have to say that it baffles me.  Any input would be great.
> 

What's the type of the two fields used in COALESCE(). Perhaps BIT ? What
PHP extension (sybase, mssql, ODBC, other) are you using ?

freddy77