智慧职教: select * from stu s join class c on s.cid=cid 与此语句查询结果一致的是（）
举一反三
- 查询选修了a001号课程的学生的最高成绩（） A: select cid, max(grade) from course where cid=’a001’ group by cid B: select cid,max(grade) from student where cid=’a001’ group by cid C: select cid, max(grade) from sc where cid=’a001’ group by cid D: select cid, max(grade) from student group by cid having cid=’a001’
- 【单选题】假设订单表 orders 用于存储订单信息, cid 代表客户编号, money 代表单次订购额,现要查询每个客户的订购次数和每个客户的订购总金额,则下列() SQL 语句可以返回正确的结果。 A. select cid,count(distinct(cid)),sum(money) from ordersgroup by cid B. select cid , count(distinct(cid)) , sum(money) fromorders order by cid C. select cid , count(cid) , sum(money) from orders orderby cid D. select cid , count(cid) , sum(money) from orders groupby cid
- 按课程号分类，统计相应的选课人数（） A: select cid, count(distinct sid) from sc group by cid B: select cid, count(*) from student group by cid C: select cid, count(distinct cid) from sc group by cid D: select cid, count(distinct sid) from student group by cid
- 统计选修了a001课程的学生的平均成绩( ) A: select cid,avg(grade) from student group by cid having cid=’a001’ B: select cid,avg(grade) from student where cid=’a001’ group by cid C: select cid,avg(grade) from course where cid=’a001’ group by cid D: select cid,avg(grade) from sc where cid=’a001’ group by cid
- 查询选修了a001号课程且成绩在60分以上的所有学生 A: select * from course where cid=’a001’ and grade>=60 B: select * from student where cid=’a001’ and grade>=60 C: select * from sc where cid=’a001’ D: select * from sc where cid=’a001’ and grade>=60