从 on/off activity 日志计算总活动时间

Question

假设我有一个支持系统。当代理可以处理票证时，他们会自行启动。当它们不再可用时，它们会自行关闭。很简单的。每次有人打开或关闭自己时，操作都会存储在数据库 table 中。像这样：

USERID    ACTION     CREATED
1         ON         2016-01-10 12:00
2         ON         2016-01-10 13:00
2         OFF        2016-01-10 15:00
1         OFF        2016-01-10 17:00
1         ON         2016-01-11 10:00
1         OFF        2016-01-11 11:00

在上面的例子中，用户 1 总共活跃了 6 小时。用户 2 总共活跃了 2 小时。如何编写一个给我这些数据的查询查询，如下所示：

USERID     TOTAL
1          6 hours
2          2 hours

该查询还需要处理用户已开启并仍处于活动状态（仅记录了开启操作，没有相应的关闭）的情况。

老实说，我什至不知道从哪里开始。我在想我可能需要创建一系列时间戳，然后用它做一些事情。又或许这只是那种写代码更容易应对的情况。无论如何，任何帮助表示赞赏。

Answer 1

设置：

create table a_table (userid int, action text, created timestamp);
insert into a_table values

(1, 'ON', '2016-01-10 12:00'),
(2, 'ON', '2016-01-10 13:00'),
(2, 'OFF', '2016-01-10 15:00'),
(1, 'OFF', '2016-01-10 17:00'),
(1, 'ON', '2016-01-11 10:00'),
(1, 'OFF', '2016-01-11 11:00'),
(1, 'ON', '2016-01-11 20:00');-- added

想法：

select distinct on (a1.userid, a1.created)
    a1.userid, a1.action, a1.created, 
    a2.userid, a2.action, a2.created, 
    coalesce(a2.created, '2016-01-11 24:00:00')- a1.created as total -- '2016-01-11 24:00:00' = the end of reported period
from a_table a1
left join a_table a2
on a1.userid = a2.userid and a1.action = 'ON' and a2.action = 'OFF' and a1.created < a2.created
where a1.action = 'ON'
order by a1.userid, a1.created, a2.created;

 userid | action |       created       | userid | action |       created       |  total   
--------+--------+---------------------+--------+--------+---------------------+----------
      1 | ON     | 2016-01-10 12:00:00 |      1 | OFF    | 2016-01-10 17:00:00 | 05:00:00
      1 | ON     | 2016-01-11 10:00:00 |      1 | OFF    | 2016-01-11 11:00:00 | 01:00:00
      1 | ON     | 2016-01-11 20:00:00 |        |        |                     | 04:00:00
      2 | ON     | 2016-01-10 13:00:00 |      2 | OFF    | 2016-01-10 15:00:00 | 02:00:00
(4 rows)

查询：

select userid, sum(total)
from (
    select distinct on (a1.userid, a1.created) 
        a1.userid, 
        coalesce(a2.created, '2016-01-11 24:00:00')- a1.created as total
    from a_table a1
    left join a_table a2
    on a1.userid = a2.userid and a1.action = 'ON' and a2.action = 'OFF' and a1.created < a2.created
    where a1.action = 'ON'
    order by a1.userid, a1.created, a2.created
) s
group by 1
order by 1;

 userid |   sum    
--------+----------
      1 | 10:00:00
      2 | 02:00:00
(2 rows)

Answer 2

SQL Fiddle Demo

我为 user_id = 3 添加了另一行 ON 而不是 OFF
nextAction 并不是真的需要它，但有助于查看 LEAD 行是什么

基本查询：

SELECT "USERID", "ACTION", "CREATED",
        LEAD("CREATED") OVER (PARTITION BY "USERID" ORDER BY "CREATED") nextDate,
        LEAD("ACTION") OVER (PARTITION BY "USERID" ORDER BY "CREATED") nextAction
FROM  activity

输出

| USERID | ACTION |                   CREATED |                  nextDate | nextAction |
|--------|--------|---------------------------|---------------------------|------------|
|      1 |     ON | January, 10 2016 12:00:00 | January, 10 2016 17:00:00 |        OFF |
|      1 |    OFF | January, 10 2016 17:00:00 | January, 11 2016 10:00:00 |         ON |
|      1 |     ON | January, 11 2016 10:00:00 | January, 11 2016 11:00:00 |        OFF |
|      1 |    OFF | January, 11 2016 11:00:00 |                    (null) |     (null) |
|      2 |     ON | January, 10 2016 13:00:00 | January, 10 2016 15:00:00 |        OFF |
|      2 |    OFF | January, 10 2016 15:00:00 |                    (null) |     (null) |
|      3 |     ON |    July, 08 2016 05:00:00 |                    (null) |     (null) |

最终查询：

COALESCE(nextDate, NOW()) 对于 ON 没有 OFF

SELECT "USERID", 
       SUM (COALESCE(nextDate, NOW()) - "CREATED") onTime
FROM (
      SELECT "USERID", "ACTION", "CREATED",
              LEAD("CREATED") OVER (PARTITION BY "USERID" ORDER BY "CREATED") nextDate,
              LEAD("ACTION") OVER (PARTITION BY "USERID" ORDER BY "CREATED") nextaction
      FROM  activity 
     ) T
WHERE   "ACTION" = 'ON'
GROUP BY "USERID"

输出

| USERID |                                                ontime |
|--------|-------------------------------------------------------|
|      1 |        0 years 0 mons 0 days 6 hours 0 mins 0.00 secs |
|      2 |        0 years 0 mons 0 days 2 hours 0 mins 0.00 secs |
|      3 | 0 years 0 mons 0 days 10 hours 47 mins 52.920889 secs |

Answer 3

您可以使用如下查询：

SELECT USERID, 
       CASE WHEN COUNT(*) = 1 THEN NOW() ELSE MAX(CREATED) END - MIN(CREATED) onTime
FROM (
  SELECT USERID, ACTION, CREATED,
         COUNT(CASE WHEN ACTION = 'ON' THEN 1 END) OVER 
              (PARTITION BY USERID ORDER BY CREATED) AS grp
  FROM mytable) AS t
GROUP BY USERID, grp

Demo here

Answer 4

测试table/data：

drop table if exists a_table;
create table a_table (seq serial primary key, userid int, action text, created timestamp);
create index a_table_i on a_table (userid, action, created);
insert into a_table (userid, action, created) values
(1, 'ON'  , '2016-01-10 12:00'),
(1, 'OFF' , '2016-01-10 17:00'),
(1, 'ON'  , '2016-01-11 10:00'),
(1, 'OFF' , '2016-01-11 11:00'),
(1, 'ON'  , '2016-01-11 20:00'),
(1, 'ON'  , '2016-01-11 21:00'), -- an "ON" without an "OFF"
(1, 'OFF' , '2016-01-11 21:00'),
(1, 'OFF' , '2016-01-11 22:00'), -- an "OFF" without an "ON"
(1, 'ON'  , '2016-01-11 21:10'),
(1, 'ON'  , '2016-01-11 21:20'), -- an "ON" without an "OFF"
(1, 'OFF' , '2016-01-11 21:30'),
(2, 'ON'  , '2016-01-10 13:00'),
(2, 'OFF' , '2016-01-10 15:00'),
(2, 'ON'  , '2016-01-11 13:00'),
(2, 'OFF' , '2016-01-12 15:00');

查询 table 请记住，可以存在许多 "ON" 用户操作而无需任何 "OFF"（反之亦然）：

SELECT  USERID, SUM(FINISHED - CREATED) AS ACTIVE_TIME
FROM    (
    SELECT  *,
        -- GET THE NEXT 'OFF' ACTION RIGTH AFTER IT
        COALESCE((SELECT CREATED FROM a_table T1 WHERE T1.USERID = T.USERID AND T1.SEQ > T.SEQ ORDER BY T1.SEQ LIMIT 1),CURRENT_TIMESTAMP) AS FINISHED
    FROM    a_table T
        -- LIST ONLY RECORDS WHERE ACTION IS 'ON' AND THE USER'S ACTION RIGHT BEFORE WAS 'OFF' OR 'NONE'
    WHERE   ACTION = 'ON'
    AND     COALESCE((SELECT ACTION FROM a_table T1 WHERE T1.USERID = T.USERID AND T1.SEQ < T.SEQ ORDER BY T1.SEQ DESC LIMIT 1),'OFF') = 'OFF'
    ) A
GROUP   BY USERID

结果：

userid   active_time
1        07:10:00
2        1 day 04:00:00

从 on/off activity 日志计算总活动时间

Calculating total active time from on/off activity log

postgresql

postgresql-9.4