On Wed, Oct 14, 2009 at 3:37 PM, Sam Mason <s...@samason.me.uk> wrote:
> On Wed, Oct 14, 2009 at 10:29:56AM -0400, Tom Lane wrote: > > Paul Hartley <phart...@gmail.com> writes: > > > ... I'm unclear > > > if PostgreSQL treats primary keys differently from unique, non-null > > > constraints. > > > > The *only* thing that the system does specially with a primary key > > constraint is that a PK creates a default column target for foreign key > > references. > > It also (silently) overrides any NOT NULL constraint doesn't it? For > example: > > CREATE TABLE x ( id INT NULL PRIMARY KEY ); > > ends up with "id" being NOT NULL, even though I asked for it to be > nullable. Not sure if it's useful for this case to be an error, though > it would be more in line with PG throwing errors when you asked for > something bad instead of making a best guess. > > if that happens, shouldn't it be an error ? after all it could potentially confuse. -- GJ
