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);