前言:
常碰到的排名需求:不并列排名,并列排名,查询指定用户排名
@rownum := @rownum + 1 :其中 := 是赋值的作用,这句话的意思是先执行@rownum + 1,然后把值赋给@rownum
(SELECT @rownum := 0) r :这句话的意思是设置rownum字段的初始值为0
正文:
不并列排名:
方法1:先排序,再对结果进行编号
SELECT t.*, @rownum := @rownum + 1 AS rownum FROM (SELECT @rownum := 0) r, (SELECT * FROM testsort ORDER BY score DESC) t;
方法2:先查询结果,再排序编号
SELECT t.*, @rownum := @rownum + 1 AS rownum FROM (SELECT @rownum := 0) r, testsort t ORDER BY t.score DESC;
结果是一样的
并列排名:
SELECT obj.uid, obj.score, CASE WHEN @rowtotal = obj.score THEN @rownum WHEN @rowtotal := obj.score THEN @rownum :=@rownum + 1 WHEN @rowtotal = 0 THEN @rownum :=@rownum + 1 END AS rownum FROM ( SELECT uid, score FROM testsort ORDER BY score DESC ) obj, (SELECT @rownum := 0 ,@rowtotal := NULL) r
查询指定用户排名:
SELECT b.* FROM ( SELECT t.*, @rownum := @rownum + 1 AS rownum FROM (SELECT @rownum := 0) r, (SELECT * FROM testsort ORDER BY score DESC) t; ) AS b WHERE b.uid = x;
參考博客:
MYSQL实现排名及查询指定用户排名功能(并列排名功能)实例代码_Mysql_脚本之家
https://www.jb51.net/article/148757.htm
Mysql实现排名函数的三种方法 - mingqing6364 - CSDN博客
https://blog.csdn.net/mingqing6364/article/details/82621840