mysql 計算排名，生成排行榜

mysql計算排名，獲取行號rowno

學生成績表數據

SELECT * FROM table_score ORDER BY score DESC;

獲取某個學生成績排名並計算該學生和上一名學生成績差，是並列排名

SELECT *,
(SELECT count(DISTINCT score) FROM table_score AS b WHERE a.score<b.score)+1 AS rank, #獲取排名，並列
(SELECT b.score FROM table_score AS b WHERE b.score>a.score ORDER BY b.score LIMIT 1)-a.score AS subtract #獲取和上一名學生成績的差 
FROM table_score AS a WHERE a.s_id = 13; #獲取學生週三的成績排名和與上一名的成績差

獲取全部學生成績排名-並列排名

SELECT *,
(SELECT count(DISTINCT score) FROM table_score AS b WHERE a.score<b.score)+1 AS rank #獲取排名-並列
FROM table_score AS a ORDER BY rank; #獲取學生成績排名

獲取全部學生成績排名，不是並列排名。計算行號進行排名

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