• 2022-06-09
    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,B

    举一反三

    内容

    • 0

      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);

    • 1

      ‏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')

    • 2

      没有选修c01课程同学的学号 SELECT<br/>sno FROM student WHERE<br/>_______________ A: cno&lt;&gt;'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)

    • 3

      基于学生—选课—课程数据库中的三个基本表:学生的信息表:STUDENT(sno, sname, sex, age, dept)主码为sno课程信息表:COURSE(cno,cname, teacher)主码为cno学生选课信息表:SC(sno, cno, grade)主码为(sno, cno) “查询没有学习成绩的学生的学号和课程号”的SQL语句是()。 A: SELECT sno, cno FROM SC WHERE grade=NULL B: SELECT sno, cno FROM SC WHERE grade IS" C: SELECT sno, cno FROM SC WHERE grade IS NULL D: SELECT sno, cno FROM SC WHERE grade="

    • 4

      有关系S(SNO, SNAME, SAGE),C(CNO, CNAME),SC(SNO, CNO, GRADE)。其中SNO是学生号,SNAME是学生姓名,SAGE是学生年龄, CNO是课程号,CNAME是课程名称,GRADE是成绩。以下( )SQL语句可以实现查询选修了'C002'号课程的学生姓名。 A: SELECT SNAME FROM S, SC WHERE S.SNO=SC.SNO AND CNO='C002' B: SELECT SNAME FROM S WHERE SNO IN (SELECT SNO FROM SC WHERE CNO='C002') C: SELECT SNAME FROM S WHERE SNO = (SELECT SNO FROM SC WHERE CNO='C002') D: SELECT SNAME FROM S WHERE SNO NOT IN (SELECT SNO FROM SC WHERE CNO='C002')