设有以下三个关系S(学号,姓名,年龄,性别,籍贯)C(课程号...答:设有以下三个关系S(学号,姓名,年龄,性别,籍贯)C(课程号,课程名,教师姓名,办公室)SC(学号,课程号,成绩)指出下列语句的含义 SELECT 书名 FROMbook WHERE 出版单位=‘高教出版社’ ORDER BY单价ASC (2)检索选修操作系统的学生姓名、课程号、和成绩。请给出其关系代数及SQL语言 (3)用SQL语言检索籍贯为上海的...
设数据库中有三个关系S(S#,SNAME,AGE,SEX) C(C#,CNAME,TEACHER)SC...答:1 select from s 2 updte sc set grade=grade+5 where c#=1 3 create view stu_info as select s#,sname,age,sex,c#,cname,grade,teacher from s,c,sc where s.s#=sc.s# and c.c#=sc.c 满意请采纳,谢谢
设有三关系S(Sno,Sname,Sage,Ssex,Sdept),SC(Sno,Cno,Grade),C(Cno,C...答:2 select distinct s.sname from s,c,sc where s.sno=sc.sno and c.cno=sc.cno and c.teacher='王勇'3 select s.sname from s,c,sc where s.sno=sc.sno and c.cno=sc.cno and c.teacher='王勇' group by s.sname having count(*)=(select count(*) from c where teacher='...