select.where...in的作用select * from pirce where id in (16,3,17,18,73) in的作用是什么是不是查询id在IN中的数据?

select.where...in的作用select * from pirce where id in (16,3,17,18,73) in的作用是什么是不是查询id在IN中的数据? 这句SQL语句是什么意思.ql=select distinct(selabel) from.sql=select distinct(selabel) from kcwl_labprosellog where isdel=0 &sqlfile& and selabel not in (select distinct(selabel) from kcwl_labprosell) 这个语句是什么作用的.说具 我有一个这样的语句select * from wspriv_adminlog tt where tt.worker_id in(select t1.worker_id from wspriv_worker t1 where t1.deptid in(select t2.deptid from wspriv_dept t2 where t2.path like '/9/58/%')) ; SQL语句:SELECT * from stu where name like %伟%;的作用是:_________________________. sql里,where a in (select .) and b in (select .)这种表示合法吗? select ** from A where A.id in (select id from B where ****) 在以下哪种情况,select ** from A whereselect ** from A where A.id in (select id from B where ****) 在以下哪种情况,此语句执行的速度快：（1）A表的记录数远多于 select * from user_info where user_name in (select user_name from user)怎么改写提高效率谢谢了. sql 语句中 select * from table where 2=1 的where2=1有什么意思和作用 在Mysql5.0 中In 用法的疑惑SELECT * FROM A where A.bigclass in(select arrchild from B) 这样子为什么查不到数据,但是写成SELECT * FROM A where A.bigclass in(1,2,35,5) 这样子就可以.注：select arrchild from B 的查询结果 SQL关于IN和EXISTS的区别?请问2者到底有什么区别啊?select MC001 from BOMMC WHERE MC001 NOT IN (SELECT MD001 FROM BOMMD)和select MC001 from BOMMC WHERE MC001 NOT EXISTS (SELECT MD001 FROM BOMMD)2个IN查出来是80,而EXISTS查出来是 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 WHERE CURRENT OF 有什么作用Select For Update有什么作用 select min(name) from tableselect * from table where id in (select min(id) from table group by name)那这样的话我是不是可以理解为他可以 完成 DISTINCT一样的效果呢? delete from A where a_id in (select id from B where b_id in (select id from C where c_id = ?))请问这句SQL语句怎么优化? 我的意思万一in语句里面的内容过多会出问题的,怎么用连接表的形式去delete? mysql 查询 not in not like和in like啥区别啊select * from aaaa where id in(1,2,3);select * from aaaa where id not in(1,2,3);select * from aaaa where tt like %as%;select * from aaaa where tt not like %as%;1 3我懂 2 4这个加了not是什 oracle查询语句 select a||','||b||','||c from table where a in('m','n') SQL语句SELECT*FORM TABLE-A WHERE name LIKE‘-mation‘ 的功能?还有SELECT*FORM TABLE-A WHERE name LIKE‘%mation‘ 的功能. select id,name from student where id in ( select id from score having count(id)>=2 );以上这段语句有没语法错误.SQL语句