連續時間問題-sql

原創

2019-08-10 07:47

問題：con_table(user_id,ttime) ttime爲用戶登陸時間，現在需要找出來連續登陸時間天數超過3天的用戶

create table con_table (
user_id int not null,
ttime datetime not null);
insert into con_table values (1,'2019-07-07 10:00:01');
insert into con_table values (1,'2019-07-07 11:00:01');
insert into con_table values (1,'2019-07-07 12:00:01');
insert into con_table values (1,'2019-07-08 10:00:01');
insert into con_table values (1,'2019-07-08 11:00:01');
insert into con_table values (1,'2019-07-09 10:00:01');
insert into con_table values (1,'2019-07-11 10:00:01');
insert into con_table values (1,'2019-07-12 10:00:01');
insert into con_table values (1,'2019-07-20 10:00:01');
insert into con_table values (1,'2019-07-21 10:00:01');
insert into con_table values (1,'2019-07-21 11:00:01');
insert into con_table values (1,'2019-07-22 10:00:01');
insert into con_table values (1,'2019-07-23 10:00:01');
insert into con_table values (2,'2019-07-07 10:00:01');
insert into con_table values (2,'2019-07-07 11:00:01');
insert into con_table values (2,'2019-07-08 12:00:01');
insert into con_table values (2,'2019-07-09 10:00:01');
insert into con_table values (2,'2019-07-10 11:00:01');
insert into con_table values (2,'2019-07-12 10:00:01');
insert into con_table values (2,'2019-07-14 10:00:01');
insert into con_table values (3,'2019-07-10 10:00:01');
insert into con_table values (3,'2019-07-11 11:00:01');
insert into con_table values (3,'2019-07-11 12:00:01');
insert into con_table values (3,'2019-07-11 13:00:01');
insert into con_table values (3,'2019-07-11 14:00:01');
insert into con_table values (3,'2019-07-20 10:00:01');

第一步：我們的時間是精確到秒的，也就是我們用戶可能一天登陸多次，所以第一步要對userid和ttime去重複

select 
	distinct
	user_id,
    date_format(ttime,'%y-%m-%d') as days
from con_table

hive中可以用to_date？或者yy-mm-dd？【待定確認】

第二步：基於上面的表，對每個用戶，每天排序

select 
    user_id,
    days,
    (select count(days) 
     from 
    	(
    	select distinct user_id,date_format(ttime,'%y-%m-%d') as days 
    	from con_table
    	) t2 
	where t2.user_id = t1.user_id and t2.days > t1.days
    ) + 1 as rnk
from
(
select 
	distinct
	user_id,
    date_format(ttime,'%y-%m-%d') as days
from con_table
) as t1;