On Mon, Nov 23, 2009 at 4:17 AM, Pavel Stehule <pavel.steh...@gmail.com> wrote: > Hello > > do you know domains? It is very similar to your proposal. >
obviously since I cited it. > constraint cannot be part of expression. > why not? NOT NULL is a contraint, UNIQUE is a contstraint. > CREATE OR REPLACE FUNCTION emptystr(text) > RETURNS bool AS $$ > SELECT $1 <> ''; -- it is SQL not C > $$ LANGUAGE sql; > > CREATE TABLE users( > username TEXT CHECK (NOT emptystr(username)), > ... this is probably the 'best' current solution. however, I'd like to be able to not have to name the column for every constraint. and domains only seem right if it's something, like a zip code, that has a very specific set of rules, that is in reality it's own type. where specifying something like 'empty' feels as generic (and arbitrary?) as null. empty is not the only example (I'm sure), just the best I can think of. > p.s. Is it related to ANSI SQL? not to my knowledge (can't say that it isn't though, I've never read the standard). -- Caleb Cushing http://xenoterracide.blogspot.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
