mysql 计算排名，生成排行榜

mysql计算排名，获取行号rowno

学生成绩表数据

SELECT * FROM table_score ORDER BY score DESC;

获取某个学生成绩排名并计算该学生和上一名学生成绩差，是并列排名

SELECT *,
(SELECT count(DISTINCT score) FROM table_score AS b WHERE a.score<b.score)+1 AS rank, #获取排名，并列
(SELECT b.score FROM table_score AS b WHERE b.score>a.score ORDER BY b.score LIMIT 1)-a.score AS subtract #获取和上一名学生成绩的差 
FROM table_score AS a WHERE a.s_id = 13; #获取学生周三的成绩排名和与上一名的成绩差

获取所有学生成绩排名-并列排名

SELECT *,
(SELECT count(DISTINCT score) FROM table_score AS b WHERE a.score<b.score)+1 AS rank #获取排名-并列
FROM table_score AS a ORDER BY rank; #获取学生成绩排名

获取所有学生成绩排名，不是并列排名。计算行号进行排名

SELECT a.*,
(@rowNum:=@rowNum+1) AS rank #计算行号
FROM table_score AS a,
(SELECT (@rowNum :=0) ) b
ORDER BY a.score DESC;