sql -- 獲取連續簽到的用戶列表

簽到表:

需求:統計連續簽到的 用戶

1.根據用戶和日期分組

select user_name, sign_date from user_sign group by user_name, sign_date order by user_name, sign_date

2.取出行號

select user_name,
       sign_date,
       if(@tmp = user_name, @rownum := @rownum + 1, @rownum := 1) as num,
       @tmp := user_name
from (select user_name, sign_date from user_sign group by user_name, sign_date order by user_name, sign_date) a,
     (select @rownum := 0, @tmp := '') b  ;

3.使用日期作對比,有則疊加,沒有則不疊加

datediff:返回2個日期之間的間隔天數

select user_name,
       sign_date,
       if(@tmp = user_name and datediff(sign_date, @date) = 1, @rownum := @rownum + 1, @rownum := 1) as num,
       @tmp := user_name,
       @date := sign_date
from (select user_name, sign_date from user_sign group by user_name, sign_date order by user_name, sign_date) a,
     (select @rownum := 0, @tmp := '', @date := '') b 

4.取出連續簽到4天的用戶列表

select * from (
select user_name,
       sign_date,
       if(@tmp = user_name and datediff(sign_date, @date) = 1, @rownum := @rownum + 1, @rownum := 1) as num,
       @tmp := user_name,
       @date := sign_date
from (select user_name, sign_date from user_sign group by user_name, sign_date order by user_name, sign_date) a,
     (select @rownum := 0, @tmp := '', @date := '') b  ) c where num=4;