外键表的级联删除(ON DELETE CASCADE的用法)

外键表的级联删除(ON DELETE CASCADE的用法)     实现两张表的级连删除呢？ 重新建立PERSON的外键，加上ON DELETE CASCADE选项试一下：   SQL> alter table person drop CONSTRAINT FK_PERSON1;   表已更改。   SQL>ALTER TABLE PERSON ADD (CONSTRAINT FK_PERSON1 FOREIGN KEY (PROFESSION) REFERENCES PERSONPROFESSION (PROFESSIONID) ON DELETE CASCADE);