创建三个表如下：
- SQL code
create table a( aid varchar(10) primary key, shuxing_a varchar(10))create table b( bid varchar(10) primary key, shuxing_b varchar(10))create table a_b( aid varchar(10) foreign key references a(aid) , bid varchar(10) foreign key references b(bid),)--插入数据：insert into a values('01', 'aa')insert into a values('02', 'bb')insert into a values('03', 'cc')insert into b values('10', 'dd')insert into b values('20', 'ee')insert into b values('30', 'ff')insert into a_b values('01', '10')insert into a_b values('02', '20')insert into a_b values('02', '30')此时我要删除a表中的‘01’，‘aa’怎么删除？还有，我要同时删除‘01’，‘aa’，和a_b表中的‘01’，‘10’又怎么删除？求大侠指点，在线等待
------解决方案--------------------
这样创建就可以直接删除了
- SQL code
create table a_b( aid varchar(10) constraint [fk_a_b_aid] foreign key references a(aid) on delete cascade, bid varchar(10) constraint [fk_a_b_bid] foreign key references b(bid) on delete cascade)