CHAR field may only have certain values - CONTRAINT

How do I make a constraint in a table for a field (CHAR(20)) that it may only accept, for example, "car" or "bike".

CREATE TABLE Things (
id INTEGER NOT NULL,
thing CHAR(30) NOT NULL,
PRIMARY KEY (id),
CONSTRAINT thingcheck CHECK (thing = "car" OR thing = "bike")
);

If I insert (1, "laptop") it still inserts! Any ideas?

Thanks very much for your time.

--开发者_Go百科- EDIT ---

As John pointed out, MySQL ignored CHECK clauses. Thanks!

how about:

ENUM('car', 'bike')

You could create a table that contains a list of the allowed values, and then set up a FOREIGN KEY constraint against it. But, really, why not just use an ENUM?

How about this,

CREATE TABLE Things (
id INTEGER NOT NULL,
thing CHAR(30) NOT NULL CHECK (thing = 'car' or thing='bike'),
PRIMARY KEY (id),
);

You should give the strings in single quote !!