Guru Prasad <pnguruji(at)yahoo(dot)com> writes:
> 'select * from junk where id != 11';
> To my surprise, it displayed all the records except those which had
> 'NULL' in the 'id' field.
This is correct per spec: NULL is not a value and it doesn't act like one.
See any discussion of SQL NULLs --- Bruce's book talks about this IIRC,
or we've been over the turf more than once in the mailing list archives.
regards, tom lane