I copypasted the following sample from
http://dev.mysql.com/doc/mysql/en/innodb-foreign-key-constraints.html (15.7.4 FOREIGN KEY):
CREATE TABLE product (category INT NOT NULL, id INT NOT NULL,
price DECIMAL,
PRIMARY KEY(category, id)) TYPE=INNODB;
CREATE TABLE customer (id INT NOT NULL,
PRIMARY KEY (id)) TYPE=INNODB;
CREATE TABLE product_order (no INT NOT NULL AUTO_INCREMENT,
product_category INT NOT NULL,
product_id INT NOT NULL,
customer_id INT NOT NULL,
PRIMARY KEY(no),
INDEX (product_category, product_id),
FOREIGN KEY (product_category, product_id)
REFERENCES product(category, id)
ON UPDATE CASCADE ON DELETE RESTRICT,
INDEX (customer_id),
FOREIGN KEY (customer_id)
REFERENCES customer(id)) TYPE=INNODB;
And got these warnings:
+---------+------+--------------------------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------------------------+
| Warning | 1287 | 'TYPE=storage_engine' is deprecated; use 'ENGINE=storage_engine' instead |
| Warning | 1266 | Using storage engine MyISAM for table 'parent' |
+---------+------+--------------------------------------------------------------------------+
MyISAM doesn't support FOREIGN KEYs, which makes the example completely nonsensical :(
NOTE: I'm using "4.1.10-nt".