如何在PostgreSQL中添加可变数量的日期？ [英] How to add a variable number of hours to a date in PostgreSQL?

问题描述

显然，PostgreSQL没有 DATEADD ，因为您可以使用 + 或 - 运算符。

我需要添加几个小时到一个日期，这是这样完成的：

  date_field + interval'8.25 hour' 
  

哪个是好的，但我需要从表中的一个字段来的小时数。将是这样的：

  date_field + interval start_time'hour'
  pre> 
 
 
我找不到任何地方如何做到这一点。这实际上是不可能的吗？
 
 
 
我不介意使用丑陋的黑客，如采取场地价值，除以3600，乘以86400.无论我需要做什么，但是我没有找到任何方法。
解决方案
由于您要添加小时 ，应该是：
  SELECT date_field + interval'1h'* start_time 
  
  start_time 可以是任何数值。
 
Apparently, PostgreSQL doesn't have DATEADD, because you can just use the + or - operators.

I need to add a number of hours to a date, which is accomplished like this:
date_field + interval '8.25 hour' 
Which is great, but I need the number of hours to come from a field in the table. Would be something like this:
date_field + interval start_time 'hour' 
I can't find anywhere how to do this. Is this actually impossible?

I don't mind resorting to ugly hacks like taking the field value and dividing by 3600, multiplying by 86400. Whatever I need to do, but I haven't found any way to do that either.
解决方案
Since you want to add hours, it should rather be:
SELECT date_field + interval '1h' * start_time
start_time can be any numerical value.

                        
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