Thread: RE: Re: [SQL] behavior of ' = NULL' vs. MySQL vs. Standards

The best solution would be to have the ODBC translate instances of '= 
NULL' into IS NULL before submitting the query to PostgreSQL. I'm 
sure this is how other vendors, like Oracle handle the issue. Well, 
probably sure... :-)

Mike Mascari
mascarm@mascari.com

-----Original Message-----
From:    Tom Ivar Helbekkmo [SMTP:tih@kpnQwest.no]
Sent:    Thursday, June 07, 2001 3:18 PM
To:    Tom Lane
Cc:    Stephan Szabo; Mark Stosberg; pgsql-sql@postgresql.org; 
pgsql-hackers@postgresql.org
Subject:    Re: [HACKERS] Re: [SQL] behavior of ' = NULL' vs. MySQL vs. 
Standards

Tom Lane <tgl@sss.pgh.pa.us> writes:

> A compromise answer might be to offer a SET variable that selects 
the
> Microsoft-compatible misimplementation.  Would that fly?

I'd say that's the best way to handle stuff like this.  If you
implement something that breaks the standard, to be compatible with
arrogant programmers at Microsoft who feel that they are above such
things, you're encouraging users to develop bad habits.  Better to
make them go "SET MICROSOFT BUG COMPATIBILITY ON" first.

To see the effect of leniency in re standards, just try to browse
around the web with a browser that rejects incorrect HTML!  :-)

Mike Mascari <mascarm@mascari.com> writes:
> The best solution would be to have the ODBC translate instances of '= 
> NULL' into IS NULL before submitting the query to PostgreSQL.

Does Access only talk to Postgres via ODBC?  (Seems plausible, but I
don't know.)  What about people copying-and-pasting queries generated
by Access; is it even possible?

I doubt that this'd really help much, in any case; it merely moves the
necessary switch from the backend to ODBC.
        regards, tom lane

Tom,

> Does Access only talk to Postgres via ODBC?  (Seems plausible, but I
> don't know.) 
Yes.
What about people copying-and-pasting queries generated
> by Access; is it even possible?

Yes, but MS Access uses some much non-standard SQL that "= Null" would
hardly be the only problem (try to build an UPDATE ... FROM in Access)

> I doubt that this'd really help much, in any case; it merely moves
> the
> necessary switch from the backend to ODBC.

Yes, but it does avoid cluttering up the PgSQL source with switches that
are only useful to a handful of users.

-Josh


______AGLIO DATABASE SOLUTIONS___________________________                                      Josh Berkus Complete
informationtechnology      josh@agliodbs.com  and data management solutions       (415) 565-7293 for law firms, small
businesses       fax 621-2533   and non-profit organizations.      San Francisco