Question

我需要一些PostgresSQL的帮助。我试图将一些记录（5-，10-，15-，20-等）分成60分钟的间隔。

我需要的是GROUP BY和AVG在给定小时内到相应小时的分钟值。

SELECT id, value, 
extract(year from GDDP.timestamp) as YEAR, 
extract(month from GDDP.timestamp) as MONTH,
extract(day from GDDP.timestamp) as DAY, 
extract(hour from GDDP.timestamp) as "HOUR",
extract(minute from GDDP.timestamp) as MINUTE,

FROM GDDP

WHERE value > 0 AND 
GDDP.timestamp  BETWEEN '2016-07-01 00:00:00' and '2016-12-31 23:55:00'

ORDER BY YEAR, MONTH, DAY, HOUR

目前，这是上述查询的结果：

id | value | YEAR | MONTH | DAY | HOUR | MINUTE
-------------------------------------------------
1  | 100   | 2016 | 07    | 01  | 1    | 05
2  | 200   | 2016 | 07    | 01  | 1    | 10
3  | 100   | 2016 | 07    | 01  | 1    | 15
4  | 300   | 2016 | 07    | 01  | 1    | 20
5  | 200   | 2016 | 07    | 01  | 1    | 25
6  | 500   | 2016 | 07    | 01  | 1    | 30

但是，我希望结果看起来像这样：

id | value  | YEAR | MONTH | DAY | HOUR
---------------------------------------
1  | 233.3  | 2016 | 07    | 01  | 1

提前感谢您的任何帮助！

Answer 1

按avg()

分组使用聚合函数year, month, day, hour

SELECT 
    min(id) as id,
    avg(value) as value, 
    extract(year from gddp.timestamp) as year, 
    extract(month from gddp.timestamp) as month,
    extract(day from gddp.timestamp) as day, 
    extract(hour from gddp.timestamp) as hour
FROM gddp
WHERE value > 0 
AND gddp.timestamp  BETWEEN '2016-07-01 01:00:00' AND '2016-12-31 01:23:00'
GROUP BY year, month, day, hour
ORDER BY year, month, day, hour;

 id |        value         | year | month | day | hour 
----+----------------------+------+-------+-----+------
  1 | 233.3333333333333333 | 2016 |     7 |   1 |    1
(1 row)

Postgres - 汇总分钟到小时

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