// IF EXISTS (SELECT name FROM m

// IF EXISTS (SELECT name FROM m if exists (select 1 from #tmp_dj_xsg212 WHERE shangplx LIKE '%冷%' if not exists (SELECT * From TA_ARTIFICER Where ARTID = @Artid)是什么意思?为什么要用到if not exists呢?在什么时候要用到 if not exists（）?它的作用是什么? if not exists(select 1 from sysobjects where type='U' and name='staffinfo')有什么作用? exists是什么意思啊exists(select * from WE_Contract_Detail_Electricity where ContractID=@ContractID) exists ERROR:- User ID already exists.Please try another one - E-mail address already exists.Please tryERROR:- User ID already exists.Please try another one- E-mail address already exists.Please try another one- Select your country.怎么翻译? oracle exists函数用法select A.DEPTNO,A.NAME FROM A WHERE EXISTS (SELECT 1 FROM B WHERE A.DEPTNO=B.DEPTNO)中的SELECT 不会是查找是1的值吧? 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 if exists 括号后的条件如何写 SELECT 在数据库中IF 和 IF EXISTS 有什么区别IF (条件)BEGIN语句快END和下面有什么区别?IF EXISTS (条件)BEGIN语句快END insert into REC_OVER(ORG_ID) select '1' from dual where not exists (select ORG_ID from REC_OVER )insert into REC_OVER(ORG_ID) select '1' from dual where not exists (select ORG_ID from REC_OVER ) 请问oracle里这样的语句,为什么在sql/plus可 SQL查询选修了全部课程的学生姓名查询选修了全部课程的学生姓名：student 是学生表 course 是选课表 sc 是课程表select snamefrom studentwhere not exists（select *from coursewhere not exists (select *from scwhere sn 数据库SQL语句中 查询选修了全部课程的学生的学号和姓名 查询选修了全部课程的学生姓名.SELECT SnameFROM StudentWHERE NOT EXISTS（SELECT *FROM CourseWHERE NOT EXISTS(SELECT *FROM SCWHERE Sno= Student.SnoAND Cno= Cours 数据库 相关子查询 SELECT SNFROM SWHERE (NOT EXISTS( SELECT *FROM CWHERE NOT EXISTS( SELECT*FROM SCWHERE SNO =S.SNOAND CNO= C.CNO)))S为学生表 C为课程表 SC为选课情况 都是缩写啦 这是查询选修所有课程的学生姓名 但 Distance is not a problem if true love exists是什么意思急 ...,even if there's no scientific evidence a hazard exists.a hazard exists是evidence的定从么?··为什么总觉得那么别扭.