day06-(mysql)
建表:
CREATE DATABASE mysqltest2; USE mysqltest2; -- 部门表 CREATE TABLE DEPT( DEPTNO INT PRIMARY KEY, -- 部门编号 DNAME VARCHAR(14) , -- 部门名称 LOC VARCHAR(13) ) ; -- 部门地址 INSERT INTO DEPT VALUES (10,'ACCOUNTING','NEW YORK'); INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS'); INSERT INTO DEPT VALUES (30,'SALES','CHICAGO'); INSERT INTO DEPT VALUES (40,'OPERATIONS','BOSTON'); -- 员工表 CREATE TABLE EMP ( EMPNO INT PRIMARY KEY, -- 员工编号 ENAME VARCHAR(10), -- 员工名称 JOB VARCHAR(9), -- 工作 MGR DOUBLE, -- 直属领导编号 HIREDATE DATE, -- 入职时间 SAL DOUBLE, -- 工资 COMM DOUBLE, -- 奖金 DEPTNO INT, -- 部门号 FOREIGN KEY(DEPTNO) REFERENCES DEPT(DEPTNO)); SELECT * FROM emp; INSERT INTO EMP VALUES (7369,'SMITH','CLERK',7902,'1980-12-17',800,NULL,20); INSERT INTO EMP VALUES (7499,'ALLEN','SALESMAN',7698,'1981-02-20',1600,300,30); INSERT INTO EMP VALUES (7521,'WARD','SALESMAN',7698,'1981-02-22',1250,500,30); INSERT INTO EMP VALUES (7566,'JONES','MANAGER',7839,'1981-04-02',2975,NULL,20); INSERT INTO EMP VALUES (7654,'MARTIN','SALESMAN',7698,'1981-09-28',1250,1400,30); INSERT INTO EMP VALUES (7698,'BLAKE','MANAGER',7839,'1981-05-01',2850,NULL,30); INSERT INTO EMP VALUES (7782,'CLARK','MANAGER',7839,'1981-06-09',2450,NULL,10); INSERT INTO EMP VALUES (7788,'SCOTT','ANALYST',7566,'1987-07-13',3000,NULL,20); INSERT INTO EMP VALUES (7839,'KING','PRESIDENT',NULL,'1981-11-17',5000,NULL,10); INSERT INTO EMP VALUES (7844,'TURNER','SALESMAN',7698,'1981-09-08',1500,0,30); INSERT INTO EMP VALUES (7876,'ADAMS','CLERK',7788,'1987-07-13',1100,NULL,20); INSERT INTO EMP VALUES (7900,'JAMES','CLERK',7698,'1981-12-03',950,NULL,30); INSERT INTO EMP VALUES (7902,'FORD','ANALYST',7566,'1981-12-03',3000,NULL,20); INSERT INTO EMP VALUES (7934,'MILLER','CLERK',7782,'1982-01-23',1300,NULL,10); -- 工资等级表 CREATE TABLE SALGRADE ( GRADE INT, -- 工资等级 LOSAL DOUBLE, -- 最低工资 HISAL DOUBLE ); -- 最高工资 INSERT INTO SALGRADE VALUES (1,700,1200); INSERT INTO SALGRADE VALUES (2,1201,1400); INSERT INTO SALGRADE VALUES (3,1401,2000); INSERT INTO SALGRADE VALUES (4,2001,3000); INSERT INTO SALGRADE VALUES (5,3001,9999); SELECT * FROM salgrade;
练习查询:
-- 1.返回拥有员工的部门名、部门号。(dept,emp) select distinct d.deptno,d.dname from dept d,emp e where e.deptno=d.deptno; -- 2.工资多于smith的员工信息。 select sal from emp where ename='smith'; select * from emp where sal>800 select * from emp where sal>(select sal from emp where ename='smith'); -- 3.返回员工和其所属领导的姓名。(自连接) select e.ename,l.ename from emp e,emp l where e.mgr=l.empno; -- 4.返回雇员的雇佣日期早于其领导雇佣日期的员工及其领导姓名。(在日期类型可以直接比较) select e.ename,l.ename from emp e,emp l where e.mgr=l.empno and e.hiredate<l.hiredate; -- 5.返回员工姓名及其所在的部门名称。 select e.ename,d.dname from emp e,dept d where e.deptno=d.deptno; -- 6.返回从事clerk工作的员工姓名和所在部门名称 select e.ename,d.dname from emp e,dept d where e.deptno=d.deptno and e.job='clerk'; -- 7.返回部门号及其本部门的最低工资。 select deptno,min(sal) from emp group by deptno; -- 8.返回销售部(sales)所有员工的姓名。 select deptno from dept where dname='sales'; select ename from emp where deptno=30 select ename from emp where deptno=(select deptno from dept where dname='sales') -- 9.返回工资多于平均工资的员工。 select avg(sal) from emp; select * from emp where sal >? select * from emp where sal >(select avg(sal) from emp) -- 10.返回与SCOTT从事相同工作的员工。 select job from emp where ename='SCOTT'; select * from emp where job=? select * from emp where job=(select job from emp where ename='SCOTT') and ename <> 'SCOTT'; -- 11.返回与30部门员工工资相同的员工姓名与工资。 select sal from emp where deptno=30 select ename,sal from emp where sal in(??) select ename,sal from emp where sal in(select sal from emp where deptno=30) -- 12.返回工资高于30部门所有员工工资水平的员工信息。 select max(sal) from emp where deptno=30 select * from emp where sal >? select * from emp where sal >(select max(sal) from emp where deptno=30) select * from emp where sal >all(select sal from emp where deptno=30); -- 13.返回部门号、部门名、部门所在位置及其每个部门的员工总数。 select deptno,count(*) from emp group by(deptno) select d.*,tmp.total from dept d,(select deptno,count(*) total from emp group by(deptno)) tmp where d.deptno=tmp.deptno; select d.*,tmp.total from dept d left join (select deptno,count(*) total from emp group by(deptno)) tmp on d.deptno=tmp.deptno; -- 14.返回员工的姓名、所在部门名及其工资。 select e.ename,d.dname,e.sal from emp e,dept d where e.deptno=d.deptno; select e.ename,d.dname,e.sal from emp e join dept d on e.deptno=d.deptno; -- 15.返回员工的详细信息。(包括部门名) select e.*,d.dname from emp e join dept d on e.deptno=d.deptno; -- 16.返回员工工作及其从事此工作的最低工资。 select job,min(sal) from emp group by job -- 17.返回不同部门经理的最低工资。 select deptno,min(sal) from emp where job='manager' group by deptno; -- 18.计算出员工的年薪,并且以年薪排序。 select ename,sal*12+ifnull(comm,0) yearsal from emp order by yearsal; -- 19.返回工资处于第四级别的员工的姓名。 select * from salgrade where grade=4; select e.ename from emp e,(select * from salgrade where grade=4) tmp where e.sal between tmp.losal and tmp.hisal; select e.ename from emp e,salgrade s where s.grade=4 and e.sal between s.losal and s.hisal ; -- 20.返回工资为二等级的职员名字、部门所在地、和二等级的最低工资和最高工资 select e.ename,d.loc,s.losal,s.hisal from emp e,salgrade s,dept d where s.grade=2 and e.deptno=d.deptno and e.sal between s.losal and s.hisal ; select e.ename,d.loc,s.losal,s.hisal from emp e join salgrade s on s.grade=2 and e.sal between s.losal and s.hisal join dept d on e.deptno = d.deptno -- 21.工资等级多于smith的员工信息。 select s.hisal from emp e,salgrade s where e.ename='smith' and e.sal between s.losal and s.hisal; select * from emp where sal >? select * from emp where sal >(select s.hisal from emp e,salgrade s where e.ename='smith' and e.sal between s.losal and s.hisal)