在postgresql选择中,将timestamp列添加到another_days列 [英] In a postgresql select, add a timestamp column to an additional_days column
问题描述
在一栏中,我有一个create_dtm保存为postgresql中的时间戳。另一列是整数wait_days。当我从数据库中拉出一行时,我想检索create_dtm + wait_days作为时间戳。
In one column I have a create_dtm saved as timestamp in postgresql. Another column is integer wait_days. When I pull a row from the database I want to retrieve create_dtm + wait_days as a timestamp.
似乎我应该能够执行此操作...我是否必须在应用程序代码中执行此操作?
It seems I should be able to do this...will I have to do it in my application code?
我的非工作示例如下:
select name, title, create_dtm + wait_days
推荐答案
您可以将整数添加到日期
,但没有时间戳
。
You can add integers to a date
but not to a timestamp
.
您只能将 interval
添加到时间戳值,因此需要将整数值转换为间隔1天:
You can only add an interval
to a timestamp value, so you need to "convert" the integer value to an interval of 1 day:
select name, title, create_dtm + interval '1' day * wait_days
from the_table;
SQLFiddle示例: http://sqlfiddle.com/#!15/891f5/1
SQLFiddle example: http://sqlfiddle.com/#!15/891f5/1
(下次请发布您收到的错误消息)
(The next time, please post the error message you get)
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