SQL之CRUD综合训练

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--已知Oracle的Scott用户中提供了三个测试数据库表--名称分别为dept,emp,salgrade。使用SQL语言完成一下操作--1,查询20号部门的所有员工信息:SELECT * FROM EMP EWHERE E.DEPTNO = 20; --2,查询奖金(COMM)高于工资(SAL)的员工信息SELECT *FROM EMPWHERE COMM > SAL;--3,查询奖金高于工资20%的员工信息SELECT *FROM EMPWHERE COMM > SAL*0.2;--4,查询10号部门中工种为MANAGER和20号部门中--工种为CLERK的员工的信息SELECT * FROM EMP EWHERE (E.DEPTNO = 10 AND E.JOB = 'MANAGER')OR (E.DEPTNO = 20 AND E.JOB = 'CLERK');--5,查询所有工种不是MANAGER和CLERK,且工资大于--或等于2000的员工的详细信息SELECT * FROM EMPWHERE JOB NOT IN ('MANAGER','CLERK')AND SAL >= 2000;--6,查询没有奖学金低于100的员工信息SELECT * FROM EMP WHERE COMM IS NULL OR COMM < 100;--7,查询员工工龄大于或等于10年的员工信息SELECT * FROM EMPWHERE MONTHS_BETWEEN(SYSDATE,HIREDATE)/12 > 10;--8,查询员工信息,要求以首字母大写的方式显示--所有员工的姓名SELECT INITCAP(ENAME) FROM EMP;--SELECT UPPER(SUBSTR(ENAME,1,1))||LOWER(SUBSTR(ENAME,2)) FROM EMP;--9,查询在2月份入职的所有员工信息SELECT * FROM EMPWHERE TO_CHAR(HIREDATE,'MM') = '02';--10,显示所有员工的姓名、入职的年份和月份--按入职日期所在的月份排序,若月份相同则按--入职的年份排序SELECT ENAME,TO_CHAR(HIREDATE,'YYYY') YEAR,TO_CHAR(HIREDATE,'MM') MONTHFROM EMPORDER BY MONTH,YEAR--11,查询‘JONES’员工及所有其直接、--间接下属员工的信息(递归算法)SELECT E.* FROM EMP ESTART WITH ENAME = 'JONES'CONNECT BY PRIOR EMPNO = MGR;--12,查询SCOTT员工及其直接、间接上级员工的信息SELECT E.*FROM EMP ESTART WITH ENAME = 'SCOTT'CONNECT BY PRIOR MGR = EMPNO;--13,查询从事同一种工作但不属于同一部门的员工信息SELECT A.ENAME,A.JOB,A.DEPTNO,B.ENAME,B.JOB,B.DEPTNOFROM EMP A,EMP BWHERE A.JOB = B.JOB AND A.DEPTNO != B.DEPTNO;--14,查询各个部门的详细信息以及部门人数、部门--平均工资SELECT D.DEPTNO,COUNT(E.EMPNO),AVG(E.SAL),D.DNAME,D.LOCFROM EMP E,DEPT DWHERE E.DEPTNO = D.DEPTNOGROUP BY D.DEPTNO,D.DNAME,D.LOC;--15,查询10号部门员工以及领导的信息SELECT *FROM EMPWHERE EMPNO IN(      SELECT MGR       FROM EMP      WHERE DEPTNO = 10)OR DEPTNO = 10;--16,查询工资为某个部门平均工资的员工信息SELECT *FROM EMPWHERE SAL IN(      SELECT AVG(SAL)      FROM EMP      GROUP BY DEPTNO);--17,查询工资高于本部门平均工资的员工的信息SELECT * FROM EMP E1WHERE SAL > (      SELECT AVG(SAL)      FROM EMP E2      WHERE E2.DEPTNO = E1.DEPTNO);--18,查询工资高于本部们平均工资的员工的信息SELECT E.*,A.AVGSALFROM EMP E,(     SELECT DEPTNO,AVG(SAL) AS AVGSAL     FROM EMP     GROUP BY DEPTNO)AWHERE A.DEPTNO = E.DEPTNO AND E.SAL > A.AVGSAL;--19,统计各个工种的人数与平均工资SELECT COUNT(*),E.JOB,AVG(E.SAL)FROM EMP EGROUP BY E.JOB;--20,查询所有员工入职以来的工作期限,用--“**年**月**日”的形式表示SELECT ENAME,TRUNC(MONTHS_BETWEEN(SYSDATE,HIREDATE)/12)||'年'||TRUNC(MOD(MONTHS_BETWEEN(SYSDATE,HIREDATE),12))||'月'||TRUNC(SYSDATE - ADD_MONTHS(HIREDATE,MONTHS_BETWEEN(SYSDATE, HIREDATE)))||'日'FROM EMP;--21,查询人数最多的部门信息SELECT * FROM DEPTWHERE DEPTNO IN(      SELECT DEPTNO       FROM       (             SELECT COUNT(*) COUNT,DEPTNO              FROM EMP             GROUP BY DEPTNO         )      WHERE COUNT IN      (             SELECT MAX(COUNT)              FROM             (                    SELECT COUNT(*) COUNT,DEPTNO                    FROM EMP                     GROUP BY DEPTNO             )       ));--22,以树状结构查询所有员工与领导--之间的层次关系SELECT SUBSTR(SYS_CONNECT_BY_PATH(ENAME,'->'),3),LEVELFROM EMPSTART WITH MGR IS NULLCONNECT BY PRIOR EMPNO = MGR;--23,部门平均薪水最高的部门编号SELECT * FROM(       SELECT *        AVG(SAL) AVGSAL,DEPTNO       FROM EMP        GROUP BY DEPTNO        ORDER BY AVGSAL DESC)WHERE ROWNUM = 1;--SELECT DEPTNO, AVG(SAL)FROM EMP GROUP BY DEPTNOHAVING AVG(SAL) =(       SELECT MAX(AVG(SAL)) AVGSAL       FROM EMP        GROUP BY DEPTNO);--24,部门平均薪水最高的部门名称SELECT D.* FROM  DEPT DWHERE DEPTNO IN(      SELECT DEPTNO       FROM EMP       GROUP BY DEPTNO      HAVING AVG(SAL)=      (             SELECT MAX(AVG(SAL)) AVGSLA             FROM EMP              GROUP BY DEPTNO      ));--25,平均薪水最低的部门名称SELECT D.DNAME FROM  DEPT DWHERE DEPTNO IN(      SELECT DEPTNO       FROM EMP       GROUP BY DEPTNO      HAVING AVG(SAL)=      (             SELECT MIN(AVG(SAL)) AVGSLA             FROM EMP              GROUP BY DEPTNO      ));--26,平均薪水等级最低的部门的部门名称SELECT D.DNAMEFROM DEPT DWHERE D.DEPTNO IN(      SELECT A.DEPTNO       FROM      (             SELECT E.DEPTNO             FROM EMP E, SALGRADE S             GROUP BY E.DEPTNO              ORDER BY AVG(S.GRADE)      )A      WHERE ROWNUM = 1);--27,部门经理人中,薪水最低的部门名称SELECT DNAME FROM DEPTWHERE DEPTNO =(      SELECT DEPTNO       FROM       (             SELECT DEPTNO              FORM EMP              WHERE JOB = 'MANAGER'             GROUP BY DEPTNO             ORDER BY MIN(SAL)      )      WHERE ROWNUM = 1);--28,比普通员工的最高薪水还要高的经理人名称SELECT ENAME FROM EMP WHERE SAL >(      SELECT MAX(SAL)      FROM EMP      WHERE JOB NOT IN       ('MANAGER','PRESIDENT'))AND JOB = 'MANAGER'OR JOB = 'PRESIDENT';--29,查询所有员工工资大于1000的部门的信息SELECT * FROM DEPTWHEREDEPTNO IN(       SELECT DEPTNO        FROM EMP       WHERE DEPTNO NOT IN       (         SELECT DISTINCT DEPTNO         FROM EMP         WHERE SAL < 1000       ));--30,查询所有员工工资都大于1000的部门的信息--以及员工信息SELECT * FROM EMP E JOIN DEPT DON D.DEPTNO = E.DEPTNOAND D.DEPTNO IN(    SELECT DEPTNO     FROM EMP    WHERE DEPTNO NOT IN    (          SELECT DISTINCT DEPTNO          FROM EMP          WHERE SAL < 1000    )     );--31,查询所有工资都在900-3000之间的员工--所在部门的员工信息SELECT *FROM DEPTWHERE DEPTNO NOT IN(      SELECT DEPTNO      FROM EMP      WHERE SAL NOT BETWEEN 900 AND 30000);--32,查询所有工资都在900-3000之间的--员工所在部门的员工信息SELECT * FROM EMP AWHERE A.DEPTNO IN(      SELECT DISTINCT E.DEPTNO       FROM EMP E      WHERE E.SAL BETWEEN 900 AND 3000);--33,查询每个员工的领导所在部门的信息SELECT D.*FROM DEPT DWHERE D.DEPTNO IN(      SELECT DISTINCT E2.DEPTNO      FROM EMP E1,EMP E2      WHERE E1.EMPNO = E2.MGR);--34,查询30号部门中工资排序前3名的员工信息SELECT * FROM (       SELECT SAL        FROM EMP       WHERE DEPTNO = 30        ORDER BY SAL DESC)EWHERE ROWNUM < 4;--35,查询工作等级为2级,1985年以后入职的工作--地点为DALLAS的员工编号、姓名和工资SELECT E.ENAME,E.EMPNO,E.SALFROM EMP E,SALGRADE S,DEPT DWHERE (E.SAL BETWEEN S.LOSAL AND S.HISAL)AND S.GRADE = 2AND TO_CHAR(E.HIREDATE,'YYYY') > 1985AND E.DEPTNO = D.DEPTNOAND D.LOC = 'DALLAS';--36,将各部门员工的工资修改为该员工所在部门--平均工资加1000UPDATE EMP E SET SAL = 1000 + (    SELECT AVG(SAL)    FROM EMP    WHERE DEPTNO = E.DEPTNO);--37,删除重复部门,只留下一项DELECT FROM DEPT DWHERE ROWID !=(      SELECT MIN(ROWID)      FROM DEPT       WHERE DNAME = D.DNAME      AND LOC = D.LOC);--38,更新员工工资为它的主管工资,奖金UPDATE EMP ESET SAL = (    SELECT SAL     FROM EMP    WHERE EMPNO = E.MGR),COMM =(     SELECT COMM      FORM EMP      WHERE     EMPNO = E.MGR);--UPDATE EMP ESET (SAL,COMM) = (    SELECT SAL, COMM    FROM EMP    WHERE EMPNO = E.MGR);--某大学图书馆为了更好管理图书,使用Oracle--数据库建立了三个表:--CARD 借书卡表:CNO(卡号),NAME(姓名),--CLASS(班级)--BOOKS图书表:BNO(书号),BNAME(书名),--AUTHOR(作者),PRICE(单价),QUANTITY(库存册数)--BORROW结束记录表:CNO(借书卡号),BNO(书号),--RDATE(还书日期)--备注:限定每人每种书只能借一本:库存册数--随借书、还书而改变--39,写出建立BORROW表的SQL语句,要求定义--主码完整性约束CREATE TABLE BORROW(       CNO NUMBER REFERENCES CARD(CNO),       BNO NUMBER REFERENCES BOOKS(BNO),       RDATE DATE,       PRIMARY KEY(CNO,BNO));--40,假定在建BOOKS表时没有定义主码,写出--BOOKS表追加定义主码的语句ALTER TABLE BOOKS ADD PRIMARY KEY(BNO);--41,将CARD表的NAME最大列宽增加到10个字符--(假定原为6个字符)ALTER TABLE CARD MODIFY NAME VARCHAR2(10);--42,为表增加一列NAME(系名),可变长,--最大20个字符ALTER TABLE CARD ADD 系名 VARCHAR2(20);--43,找出借书超过5本的读者,输出借书--卡号所借图书册数SELECT CNO,COUNT(*)FROM BORROWGROUP BY CNO HAVING COUNT(*) > 5;--44,查询借阅了“水浒”一书的读者,输出姓名班级SELECT NAME, CLASS FROM CARDWHERE CNO IN(      SELECT CNO       FROM BORROW BW, BOOKS BK      WHERE BW.BNO = BK.BNO       AND BK.NAME = '水浒');--45,查询过期未还图书,输出借阅者(卡号)--书号及还书日期SELECT * FROM BORROW WHERE RDATE < SYSDATE;--46,查询书名包括’网络‘关键词的图书,输出--书号、书名、作者SELECT BNO, BNAME,AUTHORFORM BOOKSWHERE BNAME LIKE '%网络%';--47,查询现有图书中价格最高的图书,输出--书名及作者SELECT BNAME,AUTHOR FROM BOOKSWHERE PRICE =(      SELECT MAX(PRICE)      FROM BOOKS);--48,查询当前借了“计算方法”但没有借“计算方法--习题集“的作者,输出其借书卡号,并按卡号--降序排序输出SELECT A.CNOFROM BORROW A, BOOKS BWHERE A.BNO = B.BNO AND B.BNAME = '计算方法'AND A.CNO NOT IN(    SELECT AA.CNO     FORM BORROW AA,BOOKS BB    WHERE AA.BNO = BB.BNO     AND BB.BNAME = '计算方法习题集')ORDER BY A.CNO DESC;--49,查询当前同时借有”计算方法“和组合”组合数学“--两本数的作者,输出其借书卡号,并按卡号升序排列输出SELECT DISTINCT A.CNO FROM BORROW A,BOOKS BWHERE A.BNO = B.BNOAND B.BNAME IN('计算方法','组合数学')ORDER BY A.CNO;--50,将”c01“班同学所借图书的还期都延长一周UPDATE BORROW SET RDATE = RDATE + 7WHERE CNO IN(      SELECT DISTINCT CNO       FROM CARD      WHERE CLASS = 'C01');--51,从BOOKS表中删除当前无人借阅图书记录DELETE FROM BOOKSBNO NOT IN(    SELECT DISTINCT BK, BNO     FROM BORROW BR,BOOKS BK    WHERE BR.BNO = BK.BNO);--52,如果经常按书名查询图书信息,--请建立合适的索引CREATE INDEX INX_BOOKS_BNAME ON BOOKS(BNAME); --52,在BORROW表上建立一个触发器,完成如下功能:--如果读者借阅的书名是”数据库技术应用“--就将该读者的借阅记录保存在BORROW_SAVE表中--(注:ORROW_SAVE表结构同BORROW表)CREATE TRIGGER TR_SAVE ON BORROWFOR INSERT,UPDATE AS IF@@ROW COUNT > 0INSERT BORROW_SAVE SELECT I.* FROM INSERTED I,BOOKSWHERE I.BNO = B.BNO AND B.BNAME = N'数据库应用技术';--53,建立一个视图,显示”01班学生的借书信息:--(只要求显示姓名和书名)CREATE VIEW V_VIEWASSELECT A.NAME,B.BNAMEFROM BORROW AB,CARD A, BOOKS BWHERE AB.CNO = A.CNOAND AB.BNO = B.BNO AND A.CLASS = N'01班'

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