References not being checked while creating tables?

Hi all,

I've just started learning SQL, wich is great fun. However, there's something
I don't understand, wich has to do with references.

Take this example:

CREATE TABLE test (
id serial
);

CREATE TABLE test2 (
another_id REFERENCES test(id)
);

This doesn't work, because I didn't tell the database what data type to use for
another_id. However, my point is that it _is_ able to deduct what data type
to use for another_id, as it is a reference to something I have defined.

And something related:

CREATE TABLE test (
id serial
);

CREATE TABLE test2 (
another_id text REFERENCES test(id)
);

This is accepted by the database, however, it obviously is of no use whatsoever
as the data types are incompatible.

What am I missing or overseeing here?
(Or to refrase the question: Why is it not checking this and who do I have to
suck up to in order to get this implemented? :)

Thanks in advance!

Bas van der Linden

--
B.J.J. van der Linden Amaze Internet Services V.O.F.
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1013 HA Amsterdam Fax: 020-4688337
Email: bas(at)amaze(dot)nl Web: http://www.amaze.nl/