CREATE TABLE and CHECK Clause

[Kraan Deufe]

ok here we are, 

first of all, hi to every one since i'm new to this list.

then it's my first real advanced experience with mysql, even if i've already used SQL
Server, PostgreSQL and (kof kof) Access.

well, then i'm trying to create a heavy database with many relations and check clauses. 

And i'm blocking on the check clause constraint.

So i'm asking here for precisions:
is the check clause working ? (i've seen some post saying that it is not working)
Wich kind of tables (BDB, InnoDB, ....) is supporting CHECK clauses, CASCADE DELETE,
CASCADE UPGRADE, REFERENCES.
and what is the problem with the following Query ? :

CREATE TABLE IF NOT EXISTS definitions_avantages (
    id_avantage BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY, 
    nom_avantage VARCHAR(128) NOT NULL UNIQUE CONSTRAINT CHECK (<> ''), 
    description_avantage TEXT)

thanx for your help.

Kraan Deufe
even more than Kojak ;)