表结构:
CREATE TABLE test.testsort (id int(11) NOT NULL AUTO_INCREMENT,uid int(11) DEFAULT 0 COMMENT '用户id',score decimal(10, 2) DEFAULT 0.00 COMMENT '分数',PRIMARY KEY (id))ENGINE = INNODBAUTO_INCREMENT = 1CHARACTER SET utf8COLLATE utf8_general_ciCOMMENT = '测试排序'ROW_FORMAT = DYNAMIC;
思路:可以先排序,再对结果进行编号;也可以先查询结果,再排序编号。
说明:
@rownum := @rownum + 1 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,即编号从1开始。
实现排名:
方法一:
SELECT t.*, @rownum := @rownum + 1 AS rownumFROM (SELECT @rownum := 0) r, (SELECT * FROM testsort ORDER BY score DESC) AS t;
方法二:
SELECT t.*, @rownum := @rownum + 1 AS rownumFROM (SELECT @rownum := 0) r, testsort AS tORDER BY t.score DESC;
结果:
查看指定用户排名:
方法一:
SELECT b.* FROM(SELECT t.*, @rownum := @rownum + 1 AS rownumFROM (SELECT @rownum := 0) r,(SELECT * FROM testsort ORDER BY score DESC) AS t) AS b WHERE b.uid = 222;
方法二:
SELECT b.* from(SELECT t.*, @rownum := @rownum + 1 AS rownumFROM (SELECT @rownum := 0) r, testsort AS tORDER BY t.score DESC) as b where b.uid = 222;
结果:
实现从指定用户uid为111,222,333,444,555 中获取uid为222的排名
SELECT b.* FROM(SELECT t.*, @rownum := @rownum + 1 AS rownumFROM (SELECT @rownum := 0) r,(SELECT * FROM testsort WHERE uid IN (111,222,333,444,555) ORDER BY score DESC) AS t) AS b WHERE b.uid = 222;
结果: