使用jxgl数据库，查询所有同学的选修课的门数，包括选修了课程和还未选修课程的同学。select sno,COUNT(*)______ from Students left join SC on Students.sno=SC.snogroup by sno______
举一反三
- 使用jxgl数据库，查询选修了课程的学生选修的门数，显示学号、姓名、选课门数select sno,sname,COUNT(sno)______ from Students join SC on Students.sno=SC.snogroup by sno______
- 查询选修了'数据库基础'课程的同学的学号,和这些同学选修的全部课程号和分数.select sno,cno,gradefrom ______________________ A: sc where sno in (select sno from sc join course on sc.cno=course.cno where cname='数据库基础') B: sc join course on sc.cno=course.cno where cname='数据库基础' C: sc where sno in (select sno from course where cname='数据库基础') D: sc where cno in (select cno from course where cname='数据库基础')
- 以下SQL语句中，____________可以在“学生-课程”数据库正确实现“查询选修了课程的学生总人数”。 A: SELECT COUNT(Sno)FROM SC B: SELECT COUNT(DISTINCT Sno)FROM SC C: SELECT COUNT(*)FROM SC D: SELECT SUM(Sno)FROM SC
- 查询未选修1号课程的同学的姓名,用select sno from studentwhere not exists (select sno from sc where sno=student.sno and cno='1');
- 若要求“查询选修了3门以上课程的学生的学号”,正确的SQL语句是( ) A: SELECT sNo FROM SC GROUP BY sNo WHERE COUNT(*)> 3 B: SELECT sNo FROM SC GROUP BY sNo HAVING COUNT(*)> 3 C: SELECT sNo FROM SC ORDER BY sNo WHERE COUNT(*)> 3 D: SELECT sNo FROM SC ORDER BY sNo HAVING COUNT(*)> 3