【简答题】What are the reasons for Catherine to agree to marry Edgar? What are her reasons told to Mrs. Nelly? What is the essential reason ? What can we tell about her?
【简答题】基于“学生.选课.课程”数据库中的如下三个关系: 学生基本信息:S(S#,SNAME,,AGE) 选课信息:SC(S#,C#,GRADE) 课程信息:C(C#,CNAME,TEACHER) 若要求“查询选修了5门以上课程的学生的学生号”,正确的SQL语句是( )。 A)SELECT S# FROM SC ORDER BY S# WHERE COUNT(﹡)>5 B)SELECT S# FRO...