grade_rank 查询每个项目的分组排名 top_2 中查询各个项目前二的人 然后就是匹配了 with grade_rank as ( select id,language_id,score, dense_rank()over(partition by language_id order by score desc) sc_rank from grade ), top_2 as ( select id,language_id,score,sc_rank from grade_rank where sc_rank <=2) select...