MySQL外键设置详解

p;          REFERENCES product(category, id)
                        ON UPDATE CASCADE ON DELETE RESTRICT,
                      -- 单外键
                      INDEX (customer_id),
                      FOREIGN KEY (customer_id)
                       REFERENCES customer(id)) TYPE=INNODB;
(6) 说明:
1.若不声明on update/delete,则默认是采用restrict方式.
2.对于外键约束,最好是采用: ON UPDATE CASCADE ON DELETE RESTRICT 的方式.