MySQL 如何获得两列之间的差异
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/3482033/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to get difference between 2 columns
提问by StackOverflowNewbie
I have a query that is producing something like this:
我有一个查询，正在产生这样的东西：
StartTimestamp | EndTimestamp
================================
100 | 450
--------------------------------
150 | 500
I'd like the result to also include the difference between EndTimestamp and StartTimestamp:
我希望结果还包括 EndTimestamp 和 StartTimestamp 之间的差异：
StartTimestamp | EndTimestamp | Difference
==============================================
100 | 450 | 350
----------------------------------------------
150 | 600 | 450
How do I do this in MySQL?
我如何在 MySQL 中执行此操作？
回答by Alex Martelli
If the table is named, say, t:
如果表已命名，请说t：
SELECT t.StartTimestamp, t.EndTimestamp, t.EndTimestamp - t.StartTimestamp AS Difference
FROM &c
Of course, you don't need the t.parts in the select's columns if the undecorated names StartTimestampand EndTimestampare unambiguous in the context of the rest of your query.
当然，你不需要t.，如果未修饰的名称在选择的列的部分StartTimestamp和EndTimestamp在您的查询的其余部分的情况下毫不含糊。
