[Firebird-devel] Comparing <Null> values

[Alex P. <pes...@ho...>]

Hello!

Right now I've checked, whether it's possible to compare nulls using
COALESCE. It works fine in fb1.5! For example:

select oid, fam, kem from COMMON_WORKER
where coalesce(kem, '<Unknown>') = coalesce(:kem, '<Unknown>')

Server correctly reports :kem parameter as String, and such query correctly
selects all lines where KEM IS NULL, when parameter :kem is set to null. It
seems to me that this way of null comparison is much better than using a lot
of '=' signs, and it's SQL9* compliant.

Alex.