基于这样的三个表即学生表S、课程表C和学生选课表SC,它们的结构如下:
S(S#,SN, SEX, AGE, DEPT) C(C#,CN) SC(S#,C#, GRADE)
其中:S#为学号,SN为姓名,SEX为性别,AGE为年龄,DEPT为系别,C#为课程号,CN为课程名,GRADE为成绩。
检索选修课程“C2”的学生中成绩最高的学生的学号。正确的SELECT语句是____。
A.
SELECT S# FORM SC WHERE C#=’C2’ AND GRADE >= (SELECT GRADE FORM SC WHERE C#=’CZ’)
B.
SELECT S# FORM SC WHERE C#=’C2’ AND GRADE IN (SELECT GRADE FORM SC WHERE C#=’C2’)
C.
SELECT S# FORM SC WHERE C#=’C2’ AND GRADE NOT IN (SELECT GRADE FORM SC WHERE C#=’C2’)
D.
SELECT S# FROM SC WHERE C#=’C2’ AND GRADE >= ALL (SELECT GRADE FROM SC WHERE C#=’C2’)
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