Hi All, on numerous times I had fell onto postgress complaining, that I try to create foreign key, pointing to a set not embraced within a unique key constraint. Here is the case: CREATE TABLE one (id int not null unique, info text); CREATE TABLE two (id int not null unique, ofone int references one(id), info text); now when I try to: CREATE TABLE three(one int not null, two int, info text, foreign key (one, two) references two (one, id)); I get the following error: ERROR: there is no unique constraint matching given keys for referenced table "two" But. Since table TWO has a unique constraint on column ID, the (ID, OFONE) pair will also be unique, obviously. Naturaly I can, and I do, add the requested constraint to the table TWO, but to me it looks spurious - not providing any additional constraint (which is already quearanteed by unique(ID), just a 'syntax glue'. I must have missed something here. Can someone help me understand this?
