匹配区间的思路 计算每个grade的下的数量范围的闭区间和中位数的位置,匹配后可查询出结果 select grade from (select grade, (sum(number) over(order by grade) - number + 1) as start_num, sum(number) over(order by grade) as end_num, (select floor(( SUM(number) + 1 )/ 2 ) from class_grade) AS start_t, (select floor(( SUM(number) + 2 )/ 2 ) from c...