SQL常用语句,子查询整理VIP免费

SQL 常用语句，子查询整理 一、SQL 子查询语句 1、单行子查询 select ename,deptno,sal from emp where deptno=(select deptno from dept where loc='NEW YORK')； 2、多行子查询 SELECT ename,job,sal FROM EMP WHERE deptno in ( SELECT deptno FROM dept WHERE dname LIKE 'A%')； 3、多列子查询 SELECT deptno,ename,job,sal FROM EMP WHERE (deptno,sal) IN (SELECT deptno,MAX(sal) FROM EMP GROUP BY deptno)； 4、内联视图子查询 (1)SELECT ename,job,sal,rownum FROM (SELECT ename,job,sal FROM EMP ORDER BY sal)； (2)SELECT ename,job,sal,rownum FROM ( SELECT ename,job,sal FROM EMP ORDER BY sal) WHERE rownum<=5； 5、在 HAVING 子句中使用子查询 SELECT deptno,job,AVG(sal) FROM EMP GROUP BY deptno,job HAVING AVG(sal)>(SELECT sal FROM EMP WHERE ename='MARTIN')； 6、内连接 左连接 右连接举例； select sys_user.user_id ,sys_user.user_code from sys_user inner join XZFW_BANJIE on sys_user.user_id=XZFW_BANJIE.userid 小例子： select top 10 * from sys_user where user_code not in (select user_code from sys_user where user_code like '%yzj%') select top 2 * from (select top 2 * from td.users order by us_username desc) users order by us_username desc 7、删除约束语句： alter table dbo.XZFW_SYS_USER drop CONSTRAINT FK1772E1891324F678 8、记录数查询 select count(user_pass) from sys_user select count(*) from sys_user where user_code!='admin' 9、在范围之间取值( between ... and ..用法) select sys_user.user_id,sys_user.user_name,xzfw_shoujian.caseid from sys_user inner join xzfw_shoujian on sys_user.user_id=xzfw_shoujian.userid where user_id between 5 and 100 或 select * from sys_user where user_id<10 and user_id>1 二、SQL 基本语句 下列语句部分是Mssql 语句，不可以在access 中使用。 SQL 分类： DDL—数据定义语言(Create，Alter，Drop，DECLARE) DML—数据操纵语言(Select，Delete，Update，Insert) DCL—数据控制语言(GRANT，REVOKE，COMM...