用SQL编写函数以遍历UDF中的日期范围 [英] Writing a function in SQL to loop through a date range in a UDF

问题描述

我正在尝试自动运行日期范围内的PLPGSQL函数的过程.
通常，我必须运行以下代码，每个函数调用每天生成一个表:

I am trying to automate the process of running a PLPGSQL function for a range of dates.
Typically I have to run the following code that generates a single table per day per function call:

SELECT dhcp.singleday('2012-11-24'::date, '2012-11-25'::date);
SELECT dhcp.singleday('2012-11-25'::date, '2012-11-26'::date);
SELECT dhcp.singleday('2012-11-26'::date, '2012-11-27'::date);
SELECT dhcp.singleday('2012-11-27'::date, '2012-11-28'::date);
SELECT dhcp.singleday('2012-11-28'::date, '2012-11-29'::date);
SELECT dhcp.singleday('2012-11-29'::date, '2012-11-30'::date);
SELECT dhcp.singleday('2012-11-30'::date, '2012-12-01'::date);
SELECT dhcp.singleday('2012-12-01'::date, '2012-12-02'::date);
SELECT dhcp.singleday('2012-12-02'::date, '2012-12-03'::date);
SELECT dhcp.singleday('2012-12-03'::date, '2012-12-04'::date);

是否有一个好的方法，可以通过简单的循环或函数针对任意日期范围自动执行此类操作?

Is there a good way to automate this sort of thing with a simple loop or function for an arbitrary date range?

我认为可能很难逐月处理，因此我认为最好将日期范围设置为一个月.

I am thinking it might be hard to handle the cases of going month to month so I suppose it is better assume the date range is for a single month.

推荐答案

无需功能:

select dhcp.singleday(a::date, a::date + 1)
from generate_series(
    '2012-11-24'::date,
    '2012-12-03',
    '1 day'
) s(a)

这将适用于任何日期范围.不仅是一个月内.

This will work for any date range. Not only an inside month one.

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