【单选题】语句 SELECT student_info. 学号, student_info.姓名, SUM(分数) FROM student_info , grade WHERE student_info. 学号=grade.学号 GROUP BY student_info. 学号, student_info.姓名 的查询结果是( )。
【单选题】使用查询语句 SELECT student_info.学号,student_info.姓名,SUM(分数) FROM student_info,grade WHERE student_info.学号=grade.学号 GROUP BY student_info.学号,student_info.姓名