check (constraint) on point data type?

["Jill" <jill289(at)hotmail(dot)com>]

Hi,

I'd like to limit the values that can be added to a field.

The field is of type 'point', and I'd like it to reject any values less than 0 or bigger than 1 (i.e., accept only points with values like (0.4, 0.26)).

Let's say I try to define the upper boundary by doing:

ALTER TABLE "public"."locations"  ADD CONSTRAINT "up_boundary_chk" CHECK (location < (1,1));

 

but it fails.

What am I doing wrong?

I'm using Postgres 8.2.4.1

Thanks!

Jill