Question

SQL表与表之间建立外键约束之后如何建立连级更新和删除

只要SQL语句查询代码。。莫要企业治理。。只要原创。莫要copy.

Answer 1

外键级联删除语句：后面加上on delete cascade选项。alter table B add constraint fk_ID foreign key (ID) references A(ID) on delete cascade;如许只需：delete from A where ID=nnnn; 就可以主动删除对应B表内容了。 查看更多答案>>