MySql Order By Group SELECT course_id, student_name, score, ROW_NUMBER() OVER (PARTITION BY course_id ORDER BY score DESC) AS row_num
一级标题# 一级标题二级标题## 二级标题三级标题## 三级标题第一行第二行第一行 # 注意此处需要两个空格,否则不换行第二行行标记* 行标记表格| 标题1 | 标题2 | 标题3 || :- | :- | :- || 1 | 2 | 3 || 标题1 | 标题2 | 标题3 || :- | :-
有表table,有自增id,测试不同起点查询固定条数速度:select * from news table by id desc limit 0,10耗时0.003秒select * from news table by id desc limit 10000,10耗时0.058秒select *