On 8 Nov 2010, at 16:18, Alexander Farber wrote: > Thank you, > > alter table pref_users add constraint pref_users_medals_check check > (medals >= 0); > > has worked! To clarify a bit on this; if you add a constraint, you specify its name and what type of constraint it is, before specifying the actual constraint expression. Hence the need to add 'check' (the constraint type) between 'pref_users_medals_check' (the name) and '(medals >= 0)' (the expression). Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll see there is no forest. !DSPAM:737,4cd82a7b10261263518415! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general