• 2022-05-29
    有如下的SQL语句:Ⅰ. SELECT sname FROM s, sc WHERE grade<;60Ⅱ. SELECT sname FROM s WHERE sno IN(SELECT sno FROM sc WHERE grade<;60)Ⅲ. SELECT sname FROM s, sc WHERE s.sno=sc.sno AND grade<;60若要查找分数(grade)不及格的学生姓名(sname),则以上正确的有哪些?()
    A: Ⅰ和Ⅱ
    B: Ⅰ和Ⅲ
    C: Ⅱ和Ⅲ
    D: Ⅰ、Ⅱ和Ⅲ
  • 举一反三