Re: Syntax for unique alter table statement

"GIMME" <gimme_this_gimme_that_at_yahoo.com> a écrit dans le message de news:3f12b4fb.0411051127.7a36b91d_at_posting.google.com...
> I've tried the following which doesn't to the trick ...
>
> alter table branch add constraint branch_mj_uk check (branch is unique)
>
> Note that I want to allow nulls but if an entry is not null it must be
> unique.
>
> Thanks

OK, before asking us for all the constraint syntaxes, have a look at:

http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/statements_32a.htm#2104002 http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/clauses3a.htm#998196

-- 
Regards
Michel Cadot