mysql表的级联问题

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··~

create table temp(

id char(6) not null,

gradeId char(3) not null,

mark tinyint(1),

primary key(id,gradeId)

)

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