Re: primary key and uniqueness

From: "Martin A. Marques" <martin@math.unl.edu.ar> > >Is it posible to create a table like this > >CREATE TABLE usuario ( > U_id SERIAL PRIMARY KEY UNIQUE, > U_nombre NCHAR(50), >); I don't know. Is it? Have you tried it? What happened? >The question would be if I can combine "PRIMARY KEY" with "UNIQUE". Can I >make any kind of combination of constraints? In this case PRIMARY KEY includes UNIQUE, so why would you want to? In fact, this produces error 577 "this type of constraint already exists on this column set". So, technically, the answer to your question is no. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com