如何从postgresql中的时间戳中提取句点答案

【问题标题】：How to extract periods from timestamp in postgresql如何从postgresql中的时间戳中提取句点
【发布时间】：2015-01-06 12:12:53
【问题描述】：

我需要提取并分组从每月1日到15日（包括）和从16日到月底（包括最后一天）的时间戳信息

我只每周制作一次。这是代码

 SELECT
    extract(week from dttrnreqdate) AS period, 
    SUM(bonusesCharged - bonusesCharged_rev) AS bonusesChargedForPeriod,
    SUM(bonusesWithdrawn - bonusesWithdrawn_rev) AS bonusesWithdrawnForPeriod
FROM
    ls.vstatement AS v
WHERE
    v.dttrnreqdate >= to_timestamp('2014-12-01 00:00:00', 'yyyy-mm-dd 00:00:00') AND
    v.dttrnreqdate < to_timestamp('2015-01-07 00:00:00', 'yyyy-mm-dd 00:00:00')
GROUP BY
    extract(week from dttrnreqdate)
ORDER BY
    extract(week from dttrnreqdate)
 ASC

在哪里 dttrnreqdate 是 timestamp bonusesCharged, bonusesCharged_rev, bonusesWithdrawn, bonusesWithdrawn_rev - int

那么如何提取时间戳字段的信息1-15和16-30/31

【问题讨论】：

标签： sql postgresql timestamp extract

【解决方案1】：

我很确定这回答了你的问题，但我不确定它会解决你的问题。

SELECT
    case when extract(day from dttrnreqdate) <= 15 then 'grp1'
         else 'grp2'
    end as grp,
    SUM(bonusesCharged - bonusesCharged_rev) AS bonusesChargedForPeriod,
    SUM(bonusesWithdrawn - bonusesWithdrawn_rev) AS bonusesWithdrawnForPeriod
FROM
    ls.vstatement AS v
WHERE
    v.dttrnreqdate >= to_timestamp('2014-12-01 00:00:00', 'yyyy-mm-dd 00:00:00') AND
    v.dttrnreqdate < to_timestamp('2015-01-07 00:00:00', 'yyyy-mm-dd 00:00:00')
GROUP BY
    grp
ORDER BY
    grp
 ASC;

【讨论】：