SQL> select * from a;ID ---------- aaa bbb ccc已用时间: 00: 00: 00.81 SQL> select * from b;ID ---------- aaa ccc已用时间: 00: 00: 00.20SQL> alter table a add constraint pk_a primary key (id);表已更改。已用时间: 00: 00: 00.21SQL> alter table b add constraint fk_b 2 foreign key (id) references a(id) 3 on delete cascade;表已更改。已用时间: 00: 00: 00.40 SQL> delete from a where id='aaa';已删除 1 行。已用时间: 00: 00: 00.50 SQL> select * from b;ID ---------- ccc已用时间: 00: 00: 00.20 SQL>
select operate.* from operate where adminname in (select adminname from admin);select admin.* from admin where adminname in (select distinct adminname from operate);
----------
aaa
bbb
ccc已用时间: 00: 00: 00.81
SQL> select * from b;ID
----------
aaa
ccc已用时间: 00: 00: 00.20SQL> alter table a add constraint pk_a primary key (id);表已更改。已用时间: 00: 00: 00.21SQL> alter table b add constraint fk_b
2 foreign key (id) references a(id)
3 on delete cascade;表已更改。已用时间: 00: 00: 00.40
SQL> delete from a where id='aaa';已删除 1 行。已用时间: 00: 00: 00.50
SQL> select * from b;ID
----------
ccc已用时间: 00: 00: 00.20
SQL>
(select adminname from admin);select admin.* from admin where adminname in
(select distinct adminname from operate);