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);
举一反三
- 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
- 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));
- 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')
- 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
- 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
内容
- 0
查询曾经考过100分的学生的学号，可以使用的SQL语句是：（ ） A: SELECT ALL Sno FROM SC WHERE Grade = 100; B: SELECT DISTINCT Sno FROM SC WHERE Grade = 100; C: SELECT ALL Sno FROM Student WHERE SGrade = 100; D: SELECT DISTINCT Sno FROM Student WHERE SGrade = 100;
- 1
查询选修1号课程的学生姓名的sql语句为： select sname from student where sno = (select sno from sc where cno=1);
- 2
查找学生表student中姓名的第二个字为“t”的学生学号sno和姓名sname，下面SQL语句正确的是（）。 A: SELECT sno, sname FROM student WHERE sname='_t%'; B: SELECT sno, sname FROM student WHERE sname LIKE '_t%'; C: SELECT sno, sname FROM student WHERE sname＝'%t_'; D: SELECT sno, sname FROM student WHERE sname LIKE '%t_';
- 3
以下命令是相关子查询的嵌套查询是： A: SELECT * FROM student WHERE sno IN (SELECT sno FROM sc WHERE cno = '1') B: SELECT * FROM student WHERE EXISTS (SELECT * FROM sc WHERE cno = '1' AND sc.sno = student.sno) C: SELECT sno, cno FROM sc x WHERE grade>(SELECT AVG(grade) FROM sc y WHERE y.sno = x.sno) D: 以上都是
- 4
没有选修c01课程同学的学号 SELECT<br/>sno FROM student WHERE<br/>_______________ A: cno<>'c01' B: cno!='c01' C: sno<br/>not in(SELECT sno FROM sc WHERE cno='c01') D: NOT<br/>EXISTS(SELECT * FROM sc WHERE cno='c01'AND student.sno=sno)