mysql级联查询

联合查询分为左联、内联、右联，

左联：select a.xxx,b.ccc from tableA a left join tableB b on a.id=b.id

内联：select a.xxx,b.ccc from tableA a inner join tableB b on a.id=b.id

右联：select a.xxx,b.ccc from tableA a right join tableB b on a.id=b.id

你说的是一对多吧，父子关系多难听，

一对多可以用left join 链接查询

select * from account left join tbs on account.id=tbs.cd

我刚好有这么一条sql

mysql:

1、先给B表添加主键列

alter table tableB add constraint b_PK primary key(date,channel)

2、将B表的组合主键关联到A表的外键组合键中

alter table tableB add constraint tableB_fk foreign key(date,channel) references tableA (date,channel) on DELETE CASCADE

3 delete from tableA where date =? and channel =? 就出发相关记录··~

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