oracle常用的sql

一、:插入insert语句

给指定列插入数据：insert into dept(deptno,dname)values(50,'xx');

插入全部列数据：insert into dept(deptno,dname,loc)values(60,'xx','lll'); 简写 insert into dept values(70,'xxx','llll');

二、更新update语句

更新指定数据：update dept set dname='司法部'where deptno=50;

update dept set dname='司法部',loc='china' where deptno=50;

三、删除delete语句

删除指定数据：delete from dept where deptno=70;

删除指定条件的数据：delet efrom dept where deptno>40;

四、查询select语句

查询所有：select * from emp;

指定字段查询：select ename,sal from emp;

加 where 条件：select * from emp where sal>=800;

select * from emp where sal>=1500 and job='SALESMAN';

Distinct 去重复记录；

select distinct * from emp;

Groupby 分组查询：select job,count(ename) as num from EMP t group by job;

Having 过滤分组：select job,count(ename) as num from EMP t group by job having count(ename)>=2;

Orderby 排序：select *from emp order by sal desc;

子查询：查询出基本工资大于平均工资的员工：select * from emp where sal>(select avg(sal) from emp)

联合查询： 并集（去重复）：

select * from t_user1

union

select * from t_user2;

并集：

select * from t_user1

union all

select * from t_user2;

交集：

select * from t_user1

intersect

select * from t_user2;

差集：

select * from t_user1

minus

select * from t_user2;

内连接：

select * from emp t, dept d where t.deptno=d.deptno; 类似：select * from emp e inner join deptdon e.deptno=d.deptno ;inner 可以省略；

外连接：

左外连接：select * from emp e left join dept d on e.deptno=d.deptno;

右外连接：select * from emp e right join dept d one.deptno=d.deptno;