题目
A.select sname from student where sdept=’CS‘ and sage>20
B.select sname from student where sdept=’CS‘ intersect select sname from student where sage>20
C.select sname from student where sdept=’CS‘ except select sname from student where sage<=20
D.select sname from student where sdept=’CS‘ union select sname from student where sage>20
第1题
第2题
A.默认值
B.有效性规则
C.索引
D.表之间的关系
第3题
A.select sname from student, sc where student.sno=sc.sno and cno='C002'
B.select sname from student where sno = (select sno from sc where cno='C002')
C.select sname from student where exixts (select * from sc where student.sno=sc.sno and cno='C002')
D.select sname from student where sno in (select sno from sc where cno='C002')
第4题
A.select sname from student where sno not in (select sno from sc where cno='C002')
B.select sname from student, sc where student.sno=sc.sno and cno !='C002'
C.select sname from student where exixts (select * from sc where student.sno=sc.sno and cno<>'C002')
D.select sname from student where not exixts (select * from sc where student.sno=sc.sno and cno='C002')
第5题
A.select sname from student where sdept=’CS‘ except select sname from student where sage<=20
B.select sname from student where sdept=’CS‘ intersect select sname from student where sage>20
C.select sname from student where sdept=’CS‘ and sage>20
D.select sname from student where sdept=’CS‘ union select sname from student where sage>20
第6题
A.update CS_student set sdept='IS' where sno='200215123' 1
B.delete from CS_student where sno='200215123' 2
C.insert into CS_student values('200215128','Tom','男',21,'MA') 3
D.insert into CS_student values('200215129','Mike','男',20,'CS') 4
第7题
第8题
A.10
B.35
C.45
D.50
第9题
A.(1)处填:count(*)
B.(1)处填:count(学号)
C.(2)处填:学号
D.(2)处填:课程号
第10题
A.π学号,姓名(σ课程名='数据库原理与应用'(课程∞选课∞学生))
B.π学号,姓名(σ课程名='数据库原理与应用'(课程∞选课))
C.π学号,姓名((π学号 ((σ课程名='数据库原理与应用'(课程))∞选课))∞学生)
D.π学号,姓名(σ课程名='数据库原理与应用'(课程∞学生))
为了保护您的账号安全,请在“赏学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!