下列SQL语句中，_____________可以在“学生-课程”数据库正确实现“查询选修2号课程且成绩在90分以上的所有学生的学号和姓名”。
A: SELECT Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Cno= ‘2’ AND SC.Grade > 90
B: SELECT Student.Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Grade > 90
C: SELECT Sno, SnameFROM Student, SCWHERE SC.Cno= ‘2’ AND SC.Grade > 90
D: SELECT Student.Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Cno= ‘2’ AND SC.Grade > 90
A: SELECT Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Cno= ‘2’ AND SC.Grade > 90
B: SELECT Student.Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Grade > 90
C: SELECT Sno, SnameFROM Student, SCWHERE SC.Cno= ‘2’ AND SC.Grade > 90
D: SELECT Student.Sno, SnameFROM Student, SCWHERE Student.Sno = SC.Sno AND SC.Cno= ‘2’ AND SC.Grade > 90
举一反三
- 下列SQL语句中，_____________可以在“学生-课程”数据库正确实现“查询选修2号课程且成绩在90分以上的所有学生的学号和姓名”。 A: SELECT Sno, Sname FROM Student, SC WHERE Student.Sno = SC.Sno ANDSC.Cno= ‘2’ AND SC.Grade > 90 B: SELECT Student.Sno, Sname FROM Student, SC WHERE Student.Sno = SC.Sno ANDSC.Cno=‘2’AND SC.Grade > 90 C: SELECT Sno, Sname FROM Student, SC WHERE SC.Cno=‘2’AND SC.Grade > 90 D: SELECT Student.Sno, Sname FROM Student, SC WHERE Student.Sno = SC.Sno AND SC.Grade > 90
- 下列SQL语句中，_________可以在“学生-课程”数据库正确实现“查询所有选修了1号课程的学生姓名”。 A: SELECT SnameFROM Student, SCWHERE SC.Cno= '1' B: SELECT SnameFROM Student, SCWHERE Student.Sno=SC.Sno AND SC.Cno= 1 C: SELECT Sname FROM Student WHERE Sno= (SELECT Sno FROM SC WHERE Cno= '1') D: SELECT Sname FROM Student WHERE EXISTS (SELECT * FROM SC WHERE Sno=Student.Sno AND Cno= '1')
- 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
- 在学生选课数据库中，查询选修了课程的学生的学号、姓名，SQL语句可为（ ） A: SELECT DISTINCT Sno, Sname FROM Student, SC WHERE Student.Sno = SC.Sno; B: SELECT Sno, Sname FROM Student, SC WHERE Student.Sno = SC.Sno; C: SELECT DISTINCT Sno, DISTINCT Sname FROM Student WHERE Student.Sno IN (SELECT Sno FROM SC); D: SELECT Sno, Sname FROM Student WHERE Student.Sno IN (SELECT DISTINCT Sno FROM SC);
- 查询没有选修1号课程的学生姓名（）。 A: select snamefrom student,scwhere student.sno=sc.sno and cno!='1' B: select snamefrom sno not in(select snofrom scwhere cno='1' ) C: select snamefrom sno in(select snofrom scwhere cno!='1' ) D: select snamefrom sno not exists(select*from scwhere student.sno and sc.sno and cno='1' )