查询选修了课程号为'C2'的学生号和姓名,若用下列SQL的SELECT语句表达时,错误的是()。A.SELECT S.S

Question

查询选修了课程号为'C2'的学生号和姓名，若用下列SQL的SELECT语句表达时，错误的是( )。

A．SELECT S.S#，SNAME FROM S WHERE S.S# =(SELECT S C.S# FROM SC WHERE C#='C2')

B．SELECT S.S#,SNAME FROM S，SC WHERE S.S#==S C.S# AND C#='C2'

C．SELECT S.S#，SNAME FROM S，SC WHERE S.S#=S C.S# AND C#='C2' ORDER BY S.S#

D．SELECT S.S#，SNAME FROM S WHERE S.S IN (SELECT SC.S## FROM SC WHERE C#='C2')

Answer 1

正确答案：A