MySQL分组查询条件筛选

 

1、 先排序再子查询

 

SELECT * FROM (SELECT * FROm player_level_up_log ORDER BY date DESC) AS t GROUP BY t.pid;

 

 

2、 需要进行筛选查询

SELECT pid,pname,MAX(currLv) FROM player_level_up_log GROUP BY pid;

 

3、如果需要多字段去重统计的话，怎么办呢？

 

可以使用concat字段进行连接然后在进行分组

 

 

SELECT pid,pname,weaponType,quility,MAX(clutureLv) AS 最大等级,MAX(date) AS 最后操作时间, concat(pid, weaponType, quility) AS pidWeaponTypeQuility FROM superWeapon_log GROUP BY pidWeaponTypeQuility;

 

 

 4、MySql用DATE_FORMAT截取DateTime字段的日期值，用 DATE_FORMAT 来格式化日期字段

 

SELECT DATE_FORMAT(crt_time,'%Y-%m-%d') FROM ad_n_advertise_t

 

 

执行结果：