Re: not null - trivial, unexpected behavior

John Scott <jmscott@yahoo.com> writes:
> select count(*) from A where b = null;      /* Returns 1, ok */
> select count(*) from A where b != null;     /* Returns 0 ... not ok! */

Uh ... there have been several threads about this just in the past
couple days.  See for example
http://www.ca.postgresql.org/mhonarc/pgsql-sql/2001-06/msg00102.html
and followups.
        regards, tom lane