sql 练习

Posted 2021-02-20 recommencer

-- DROP TABLE IF EXISTS `dept`;
-- CREATE TABLE `dept` (
-- `deptno` int PRIMARY KEY ,
-- `dename` VARCHAR(14) ,
-- `loc` VARCHAR(13)
-- );
-- 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‘);
--
--
-- DROP TABLE IF EXISTS emp;
-- CREATE TABLE emp (
-- empno int PRIMARY KEY,
-- ename VARCHAR(10),
-- job VARCHAR(9),
-- mgr INT,
-- hiredare DATE,
-- sal DOUBLE,
-- comm DOUBLE,
-- deptno INT
-- );
-- ALTER TABLE emp ADD CONSTRAINT FOREIGN KEY emp(deptno) REFERENCES dept (deptno);
-- 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,‘1987-07-03‘,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,‘1981-01-23‘,1300,NULL,10);

-- DROP TABLE IF EXISTS salgrade;
-- CREATE TABLE salgrade (
-- grade INT,
-- losal DOUBLE,
-- hisal DOUBLE
-- );
-- 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);

-- 1、查询部门30中员工的详细信息
-- SELECT * from emp WHERE deptno=30;
-- 2、找出从事clerk工作的员工的编号、姓名、部门号
-- SELECT empno ,ename,deptno from emp WHERE job=‘CLERK‘;
-- 3、检索出奖金多于基本工资的员工信息
-- SELECT * from emp where comm > sal;
-- 4、检索出奖金多余基本工资60%的员工
-- SELECT * FROM emp where comm >sal*0.6
-- 5、找出10部门的经理，20部门的员工信息
-- SELECT * from emp where deptno=10 AND job=‘manager‘ or deptno=20 AND job=‘clerk‘;
-- 6、找出10部门的经理，20部门的员工信息或既不属于经理也不属于职员，但工资高于2000的员工
-- SELECT * from emp where deptno=10 AND job=‘manager‘ or deptno=20 AND job=‘clerk‘ or job not in(‘manager‘,‘clerk‘) AND sal>2000;
-- 7、找出获得奖金的员工
-- SELECT * from emp WHERE comm >0
-- 8、找出奖金少于100或没有获得奖金的人
-- SELECT * from emp WHERE comm<100 or comm is null
-- 9、找出姓名以ABS开头的员工
-- SELECT * from emp WHERE ename like ‘a%‘ or ename like ‘b%‘ or ename like ‘s%‘
-- 10、找到名字长度为6个字符的员工
-- SELECT * from emp WHERE length(ename)=6
-- 11、找出名字中不包含r的员工
-- SELECT * from emp WHERE ename not like ‘%r%‘
-- 12、返回员工的信息，并按照姓名进行排序
-- SELECT * from emp  ORDER BY ename asc
-- 13、按照工作降序、工资升序排列
-- SELECT * from emp ORDER BY job desc , sal asc
-- 14、计算员工的日薪资
-- SELECT ename,sal/30 as ‘avg(sal)‘ from emp
-- 15、找出姓名中包含a的员工
-- SELECT * from emp WHERE ename LIKE ‘%a%‘
-- 16、返回拥有员工的部门名和部门号
-- SELECT a.ename,a.deptno,b.dename from emp a LEFT JOIN dept b on a.deptno=b.deptno
-- 17、工资水平多于smith的员工信息。
-- SELECT *FROM emp WHERE sal > (SELECT sal from emp WHERE ename=‘smith‘)
-- 18、返回员工和所属经理的姓名。
-- SELECT a.ename,b.ename from emp a LEFT JOIN emp b on a.mgr=b.empno WHERE b.job=‘manager‘
-- 19、返回雇员的雇佣日期早于其经理雇佣日期的员工及其经理姓名。
-- SELECT a.ename,b.ename from emp a  INNER JOIN emp b on a.mgr=b.empno WHERE a.hiredare<b.hiredare
-- 20、返回员工姓名及其所在的部门名称。
-- SELECT a.ename,b.dename FROM emp a LEFT JOIN dept b on a.deptno=b.deptno
-- 21、返回从事clerk工作的员工姓名和所在部门名称。
-- SELECT a.ename,b.dename from emp a LEFT JOIN dept b on a.deptno=b.deptno WHERE a.job=‘clerk‘
-- 22、返回部门号及其本部门的最低工资。
-- SELECT deptno,min(sal) from emp  GROUP BY deptno
-- 23、返回销售部(sales)所有员工的姓名。
-- SELECT a.ename from  emp a LEFT JOIN dept b on a.deptno=b.deptno WHERE b.dename=‘sales‘
-- 24、返回工资水平多于平均工资的员工。
-- SELECT * from emp WHERE sal> (SELECT avg(sal) FROM emp)
-- 25、返回与SCOTT从事相同工作的员工。
-- SELECT * from emp WHERE job in(  SELECT a.job from emp a WHERE a.ename=‘scott‘)
-- 26、返回与30部门员工工资水平相同的员工姓名与工资。
-- SELECT * from emp WHERE sal in(SELECT sal from emp WHERE deptno=30)
-- 27、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 a.deptno,b.dename,b.loc,count(*) as cc from emp a LEFT JOIN dept b on a.deptno=b.deptno GROUP BY a.deptno
-- 26、返回员工的姓名、所在部门名及其工资。
-- SELECT a.ename,b.dename,a.sal from emp a ,dept b WHERE a.deptno=b.deptno
-- 27、返回员工的详细信息。(包括部门名)
-- SELECT * from emp,dept,salgrade WHERE emp.deptno=dept.deptno AND emp.sal BETWEEN losal AND hisal
-- 28、返回员工工作及其从事此工作的最低工资。
-- SELECT * ,min(sal) from emp GROUP BY job
-- 29、返回不同部门经理的最低工资。
-- SELECT * ,min(sal) FROM emp WHERE job=‘manager‘  GROUP BY deptno
-- 30、计算出员工的年薪，并且以年薪排序
-- SELECT *,sal*12 as nianxin from emp ORDER BY nianxin  asc
-- 31、返回工资处于第四级别的员工的姓名。
-- SELECT * from emp a ,salgrade b WHERE a.sal BETWEEN losal AND hisal  AND grade=4
-- 32、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 * FROM emp a ,salgrade b,dept c WHERE sal BETWEEN losal AND hisal AND grade=2  AND a.deptno=c.deptno
-- 33、返回工资为二等级的职员名字、部门所在地、二等级员工工资的最低工资和最高工资
-- SELECT ename,loc ,(SELECT min(sal) from emp,salgrade WHERE sal BETWEEN losal and hisal AND grade=2),(SELECT max(sal) from emp,salgrade WHERE sal BETWEEN losal and hisal AND grade=2)
-- from  emp ,dept ,salgrade WHERE sal BETWEEN  losal AND hisal AND grade=2 AND emp.deptno=dept.deptno
-- 34、工资等级多于smith的员工信息。
--   SELECT * from emp WHERE sal>(SELECT hisal FROM emp ,salgrade WHERE ename=‘smith‘ AND sal BETWEEN losal AND hisal)

-- select * from emp,salgrade where sal between losal and hisal and grade >(select grade from emp,salgrade where sal between losal
--  and hisal and ename = ‘smith‘);