select * from teacher where s_id in(select s_id from student) s_id栏位在student表中无,但是不报错建立如下两个表student(id,name)teacher(id,name,s_id)为什麽以下这个SQL不报错,S_ID栏位在student表中根本不存在select * f

select * from book limit , select * from a union select * from b 能详细说下么 select from 表 和select from [表]有什么不同? select count(*) from 怎么使用 select count(1) from emp select * into dept2 from dept 1' union select * from [ADM] union select * 请问 select top 1 1 from ... // IF EXISTS (SELECT name FROM m select * into b from a where 11 SQL 语句 SELECT * FROM {{table}} WHERE `fleet_end_time` SELECT ms sql :select * from (select *from b) as xxx where 和 select * from (select *from b) xxx where区select * from (select *from b) as xxx where…… 和 select * from (select *from b) xxx where……的区别别告诉我是一样的.因为我有一 select max(account_id ) from(select top 5 account_id from account)子查询没起作用为什么? select * from user_info where user_name in (select user_name from user)怎么改写提高效率谢谢了. select * from (select a.*,rownum aa from table a ) where aa=10 数据库中select into from 和 insert into select的区别 请问sql=select * from 招聘信息 order by id