Sql 如何删除重复项以便表中只存在对?
我有一个ticket_事件表,显示签入和签出时间戳Sql 如何删除重复项以便表中只存在对?,sql,postgresql,Sql,Postgresql,我有一个ticket_事件表,显示签入和签出时间戳 timestamp type 2018-12-26 02:46:01 IN 2018-12-26 02:46:13 IN 2018-12-26 03:17:57 OUT 2018-12-26 04:12:13 IN 2018-12-26 04:12:25 IN 2018-12-26 04:35:41 OUT 2018-12-26 04:35:53 OUT 2018-12-26 05:11:05 IN 2018-12-
timestamp type
2018-12-26 02:46:01 IN
2018-12-26 02:46:13 IN
2018-12-26 03:17:57 OUT
2018-12-26 04:12:13 IN
2018-12-26 04:12:25 IN
2018-12-26 04:35:41 OUT
2018-12-26 04:35:53 OUT
2018-12-26 05:11:05 IN
2018-12-26 06:03:42 OUT
2018-12-26 06:03:55 OUT
2018-12-26 06:04:43 IN
2018-12-26 06:04:50 IN
2018-12-26 06:28:07 OUT
2018-12-26 06:28:19 OUT
2018-12-26 07:00:11 IN
2018-12-26 07:00:22 IN
2018-12-26 07:19:13 OUT
2018-12-26 07:59:21 IN
2018-12-26 08:24:57 OUT
我只希望表中出现IN-OUT对,没有连续的IN或OUT。例如,我想:
timestamp type
2018-12-26 02:46:01 IN
2018-12-26 03:17:57 OUT
2018-12-26 04:12:13 IN
2018-12-26 04:35:41 OUT
2018-12-26 05:11:05 IN
2018-12-26 06:03:42 OUT
2018-12-26 06:04:43 IN
2018-12-26 06:28:07 OUT
2018-12-26 07:00:11 IN
2018-12-26 07:19:13 OUT
2018-12-26 07:59:21 IN
2018-12-26 08:24:57 OUT
有人知道用sql查询来实现这一点吗
我现在的问题是
select timestamp, type from ticket_events where ticket_uuid='value'
要删除前一行具有相同类型的任何行。因此:
select timestamp, type
from (select t.*,
lag(type) over (order by timestamp) as prev_type
from ticket_events t
) t
where prev_type <> type or prev_type is null;
如果要删除“有问题”的行,可以执行以下操作--假设时间戳
是唯一的:
delete from ticket_events
using (select t.*,
lag(type) over (order by timestamp) as prev_type
from ticket_events t
) tt
where tt.timestamp = t.timestamp and
tt.prev_type = t.type;
这是一个缺口和孤岛问题 您可以使用
ROW\u NUMBER
window函数获取间隙,然后使用groupby
withmin
SELECT MIN(timestamp) "timestamp",
type
FROM (
SELECT *,
ROW_NUMBER() OVER(ORDER BY timestamp)-
ROW_NUMBER() OVER(PARTITION BY type ORDER BY timestamp) gap
FROM ticket_events
where ticket_uuid='value'
) t1
GROUP BY gap,type
ORDER BY MIN(timestamp)
:
| timestamp | type |
|----------------------|------|
| 2018-12-26T02:46:01Z | IN |
| 2018-12-26T03:17:57Z | OUT |
| 2018-12-26T04:12:13Z | IN |
| 2018-12-26T04:35:41Z | OUT |
| 2018-12-26T05:11:05Z | IN |
| 2018-12-26T06:03:42Z | OUT |
| 2018-12-26T06:04:43Z | IN |
| 2018-12-26T06:28:07Z | OUT |
| 2018-12-26T07:00:11Z | IN |
| 2018-12-26T07:19:13Z | OUT |
| 2018-12-26T07:59:21Z | IN |
| 2018-12-26T08:24:57Z | OUT |
| timestamp | type |
|----------------------|------|
| 2018-12-26T02:46:01Z | IN |
| 2018-12-26T03:17:57Z | OUT |
| 2018-12-26T04:12:13Z | IN |
| 2018-12-26T04:35:41Z | OUT |
| 2018-12-26T05:11:05Z | IN |
| 2018-12-26T06:03:42Z | OUT |
| 2018-12-26T06:04:43Z | IN |
| 2018-12-26T06:28:07Z | OUT |
| 2018-12-26T07:00:11Z | IN |
| 2018-12-26T07:19:13Z | OUT |
| 2018-12-26T07:59:21Z | IN |
| 2018-12-26T08:24:57Z | OUT |