Question

如何级联删除多个表的记录？

现有A B C三个表 主键都是snum， 现要实现删除A表中某个记录（比如snum为1的记录）,如何级联删除B C表中snum为1的记录？？
有没有这样删的： delete A,B,C where.....

Answer 1

如果b，c表的snum是参照A的snum
alter table B
add constraint snum
foreign key(snum) references A(snum)
on delete cascade;
alter table C
add constraint snum
foreign key(snum) references A(snum)
on delete cascade;
delete from A where snum=1;
commit;

Answer 2

写成一条语句即可：
DELETE A WHERE snum=1 DELETE B WHERE snum=1 DELETE C WHERE snum=1

Answer 3

delete A.snum from A
join B
on A.snum=B.snum
join c
on B.snum=A.snum
where snum='1'
试试