MariaDB 查找月份的第一天并转换为 UTC

Question

我正在使用 MariaDB，我的记录都存储在 UTC 中，但是我希望能够根据我的本地时区找到过去 12 个日历月内的那些记录。

这是我采取的步骤：

SELECT
    CURRENT_TIMESTAMP() AS Current_Date_And_Time_In_UTC,
    CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland') AS Current_Date_And_Time_In_Auckland,
    DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) AS Date_In_Auckland,
    LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 1 MONTH) AS Last_Day_Previous_Month_In_Auckland,
    LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 1 MONTH) + INTERVAL 1 DAY AS First_Day_Current_Month_In_Auckland,
    TIMESTAMP(LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 1 MONTH) + INTERVAL 1 DAY, MAKETIME(0,0,0)) AS First_Day_At_Midnight_Current_Month_In_Auckland,
    CONVERT_TZ(TIMESTAMP(LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 1 MONTH) + INTERVAL 1 DAY, MAKETIME(0,0,0)), 'Pacific/Auckland','UTC') AS First_Day_At_Midnight_Current_Month_In_UTC

这导致我将其用作我的范围：

SELECT
    CONVERT_TZ(TIMESTAMP(LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 13 MONTH) + INTERVAL 1 DAY, MAKETIME(0,0,0)), 'Pacific/Auckland','UTC') AS Start_DateTime_In_UTC,
    CONVERT_TZ(TIMESTAMP(LAST_DAY(DATE(CONVERT_TZ(CURRENT_TIMESTAMP(),'UTC','Pacific/Auckland')) - INTERVAL 1 MONTH) + INTERVAL 1 DAY, MAKETIME(0,0,0)), 'Pacific/Auckland','UTC') AS End_DateTime_In_UTC

有没有更简单的方法可以达到同样的效果？

Answer 1

如果您有一列 timestamp 数据类型，则根本不需要偏移。

documentation states:

If a column uses the TIMESTAMP data type, then any inserted values are converted from the session's time zone to Coordinated Universal Time (UTC) when stored, and converted back to the session's time zone when retrieved.

假设您的会话时区设置为您当地的时区，过滤过去 12 个月的列应该很简单：

where myts >= date_format(current_date, '%Y-%m-01') - interval 12 month
  and myts <  date_format(current_date, '%Y-%m-01')

MariaDB 查找月份的第一天并转换为 UTC

MariaDB Find the First Day of the Month and Convert to UTC

sql

timezone

datetime

utc

mariadb