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
    
     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

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) ) bORDER BY a.score DESC;