数据库实验四答案(共7页).docx

精选优质文档-倾情为你奉上数据库实验四答案 -实验四-1定义“IS”系学生基本情况视图V_IS 并查询结果；create view V_ISasselect *from Swhere Sdept='IS'with check option;select *from V_IS;-2将S，C，SC表中学生的学号，姓名，课程号，课程名，成绩定义为视图V_S_C_G并查询结果;create view V_S_C_Gasselect S.Sno,Sname,C.Cno,Cnamefrom S,C,SCwhere S.Sno=SC.Sno and C.Cno=SC.Cno;select *from V_S_C_G;-3将各系学生人数，平均年龄定义为视图V_NUM_AVG并查询结果;create view V_NUM_AVGasselect