欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

sql语句合集大全(个人总结)

程序员文章站 2022-05-03 19:35:56
--查找emp表 select * from emp; --查找emp表的sal select a.SAL from emp a; --查找emp表的ename sele...

--查找emp表

select * from emp;

--查找emp表的sal

select a.SAL from emp a;

--查找emp表的ename

select a.ename from emp a;

--emp表的sal*10

select a.SAL*10 from emp a;

--emp表的sal的平均值

select avg(a.sal) from emp a;

--emp表的sal的总和

select sum(a.sal) from emp a;

--emp表的sal的max

select max(a.sal) from emp a;

--emp表的sal的min

select min(a.sal) from emp a;

--emp表中sal<1000的信息

select * from emp where sal<1000;

--ename中含有A的信息

select ename from emp where ename like'%A%';

--emp中ename不含有A的信息

select * from emp where ename not like'%A%';

--查询系统时间

select sysdate from dual;

--计算薪资小于5000的员工的工资总和

select sum(sal) from emp where sal<5000 ;

--计算工资不高于平均工资的工资总和

select sum(sal) from emp where sal<(select avg(sal) from emp);

--计算工资小于4000的员工的平均工资

select avg((select sum(sal) from emp where sal<4000)) from emp;

--查询薪水低于100000的员工姓名和sal

select ename,sal from emp where sal<100000;

--计算20号部门的员工的最高工资和最低工资

select max(sal),min(sal) from emp where deptno=20;

--查询工资大于1000,并且是20号部门的员工的全部信息

select * from emp where sal>1000 and deptno=20;

--求最高工资的员工的员工姓名和部门名称

select ename,deptno,sal from emp where sal=(select max(sal) from emp);

--将员工薪水小于5000且部门平均薪水大于1000的部门标号列出,按部门平均薪水降序排序

select deptno from emp where sal<5000 group by deptno having avg(sal) >1000;

select sal from emp order by sal desc;

Order by *** desc

--查找表emp

select * from emp ;

--根据用户名“Smiths”查找他所在的部门

select deptno from emp where ename='SMITH';

--查询每个部门的最高工资的人员名称

select e.ename,e.deptno,e.sal from (select deptno as did ,max(sal) as m from emp group by deptno ) s,emp e,dept d where e.sal=s.m and s.did=e.deptno and d.deptno=e.deptno;

--查询“Jones”之后第一个进入公司的人

select * from emp where hiredate=(select min(hiredate) from emp where hiredate>(select hiredate from emp where ename='JONES')) ;

--5.查找工资最高的部门名称和工资最低的部门名称及工资

select d.dname,e.sal from emp e,dept d where e.deptno=d.deptno and sal=(select max(m) from (select deptno,max(sal) as m from emp e group by deptno) s)

union

select d.dname,e.sal from emp e,dept d where e.deptno=d.deptno and sal=(select min(m) from (select deptno,min(sal) as m from emp e group by deptno) s)

--创建表

create table student(

StudentId number (6),--学号

LoginPwd varchar(20),--密码

StudentName varchar(50),--姓名

Sex char(2),--性别

Gradeld Number(6),--所在年级

Phone number(15),--联系电话

Address varchar2(255),--现住址

BornDate Date,--出生日期

Emile varchar2(50)--电子邮件

);

--添加数据

insert into student values(1001,'123456','赵六','男',1507,120,'北京','23-5月-1995','@10422');

insert into student values(1002,'123456','王五','女',1507,110,'北京','23-5月-1995','@10422');

insert into student values(1003,'123456','张三','男',1507,120,'北京','23-5月-1995','@10422');

insert into student values(1004,'123456','李四','女',1507,110,'北京','23-5月-1995','@10422');

--提交

commit;

--查询此表

select * from student;

--根据条件修改

update student set studentname='孙七',loginpwd='666666' where studentid=1001;

select * from student;

--根据条件删除

delete from student where studentid=1002;

select * from student;

--增加字段

ALTER TABLE 表名称 ADD(列名称 数据类型 [DEFAULT 默认值],列名称 数据类型 [DEFAULT 默认值],…)

--删除此表

drop table student;

--B卷 创建表空间

create tablespace mytestspace datafile 'e:week3.dbf' size 2M;

--创建用户

create user zhangsan identified by zhangsan default tablespace mytestspace

temporary tablespace temp;

--创建角色并授权

create role fang;

grant create table to fang;

grant fang to zhangsan;

grant dba to zhangsan;

--创建表

create table teacher (

tid number primary key,

tname varchar2(50),

tdate date,

address varchar2(100)

);

select * from teacher;

--创建序列

create sequence teachers_sequence minvalue 1 maxvalue 100 (最小值,最大值)cycle (循环)increment by 1(步长值) start with 1(从1开始);

insert into teacher values(teachers_sequence.nextval,'小李','01-1月-1999','北京');

insert into teacher values(teachers_sequence.nextval,'小张',to_date('1982-1-1','yyyy-mm-dd'),'北京');