同时选修了‘数据结构’和‘操作系统’2门课程的同学学号、姓名。select student.sno,sname from student,sc,coursewhere student.sno=sc.sno and course.cno=sc.cnoand _________________________________________________
A: cname='数据结构' and student.sno in(select sno from sc,course where sc.cno=course.cno and cname='操作系统')
B: cname='操作系统' and student.sno in(select sno from sc,course where sc.cno=course.cno and cname='数据结构')
C: cname='数据结构' and cname='操作系统'
D: student.sno in(select sno from sc,course where sc.cno=course.cno and cname='操作系统'and cname='数据结构')
A: cname='数据结构' and student.sno in(select sno from sc,course where sc.cno=course.cno and cname='操作系统')
B: cname='操作系统' and student.sno in(select sno from sc,course where sc.cno=course.cno and cname='数据结构')
C: cname='数据结构' and cname='操作系统'
D: student.sno in(select sno from sc,course where sc.cno=course.cno and cname='操作系统'and cname='数据结构')
举一反三
- 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')
- 查询没有选数据库基础课程的同学学号和姓名。select sno,sname from student where ____________(select ______ from sc ,course where _______________ and cname='数据库基础') A: not exists；* ; course.cno=sc.cno and student.sno=sno B: not exists；sno ; course.cno=sc.cno and student.sno=sc.sno C: sno not in ; sno ; course.cno=sc.cno D: sno not in ; * ; course.cno=sc.cno and student.sno=sc.sno
- 下列查询中,属于相关子查询的有（）。 A: SELECT * FROM student WHERE sno IN (SELECT sno FROM sc WHERE cno='1'); B: SELECT sno, cno FROM SC x WEHRE grade>=(SELECT AVG(grade) FROM SC y WHERE y.sno = x.sno); C: SELECT sname FROM student WHERE EXISTS(SELECT * FROM sc WHERE sno=student.sno AND cno='1'); D: SELECT sname FROM student WHERE NOT EXISTS(SELECT * FROM course WHERE NOT EXISTS(SELECT * FROM sc WHERE sc.sno=student.sno AND sc.cno=course.cno));
- 查询每个学生的学号、姓名、选修的课程名及成绩，下列（)的操作是正确的。 A: select student,sno,sname,grade from student,sc where student.sno=sc.sno and sc.cno=course.cno B: select student,sno,sname,grade from student,sc,cource where student.sno=sc.sno C: select student,sno,sname,grade from student,sc,cource where sc.cno=course.cno D: select student,sno,sname,grade from student,sc,cource where student.sno=sc.sno and sc.cno=course.cno
- 现有关系student (sno,sname,sex,age)course(cno,cname,credit）sc(sno,cno,socre)查询选了102号课程的学生的学号，姓名和成绩select student.sno,_____,_____from _____,______where ____________ and 课程号='102'