1、数据库习题作业重点（第 2-3-4 章）2.6 设有关系 R 和 S：R A B C S A B C3 6 7 3 4 52 5 7 7 2 37 2 34 4 3计算 RS，R-S，RS，RS， 3,2（S）, B10ORDER BY 2 DESC，1；检索学号比 WANG 同学大，而年龄比他小的学生姓名。SELECT SNAMEFROM SWHERE S#ALL(SELECT S# FROM SWHERE SNAME=WANG)AND AGE(SELECT AVG(AGE)FROM SWHERE SEX=F)；求年龄大于所有女同学年龄的男学生的姓名和年龄。SELECT SNAME, AGE
2、FROM SWHERE SEX=MAND AGEALL(SELECT AGEFROM SWHERE SEX=F)；【312】解：INSERT INTO CVALUES(C8， VC+， T6)；法一：INSERT INTO FACULTY(TNAME)SELECT DISTINCT TNAMEFROM (SELECT TNAME，CC# ，AVG(SCORE)FROM T, C, SCWHERE TT#=C T# AND CC#=SC C#GROUP BY TNAME，CC#)AS RESULT(TNAME，C#，AVGSCORE) AS XWHERE 8070；UPDATE SCSET SC
3、ORE=SCORE * 1.05WHERE C#=C4AND SCORE70 THEN 1.04ELSE l.05ENDWHERE C#=C4;UPDATE SCSET SCORE=SCORE * 1.05WHERE SCORE50 AND SEX=M；SELECT EMPE#，ENAMEFROM EMP, WORKSWHERE EMP.E#=WORKSE# AND SALARY1000 AND SEX=M；SELECT AE#，AENAMEFROM EMP A，WORKS B ，WORKS CWHERE AE#=BE# AND B E#=CE#AND BC#=C4 AND CC#=C8 ；S
4、ELECT AE#，AENAMEFROM EMP A，WORKS B ，COMP CWHERE AE#=BE# AND B C#=C #AND CNAME=联华公司 AND SALARY1000 AND SEX=M；SELECT E# ，COUNT(C#) AS NUM，SUM(SALARY) AS SUM_SALARYFROM WORKSGROUP BY E#;SELECT X.E#FROM WORKS XWHERE NOT EXISTS(SELECT *FROM WORKS YWHERE E#=E6AND NOT EXISTS(SELECT *FROM WORKS ZWHERE ZE#=XE# AND ZC#=Y C# )；SELECT AE#，AENAME
