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      1. 如何在 MySQL 中为字段或列设置别名?

        How to alias a field or column in MySQL?(如何在 MySQL 中为字段或列设置别名?)

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                  本文介绍了如何在 MySQL 中为字段或列设置别名?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着跟版网的小编来一起学习吧!

                  问题描述

                  我正在尝试做这样的事情.但我收到一个未知的列错误:

                  I'm trying to do something like this. But I get an unknown column error:

                  SELECT SUM(field1 + field2) AS col1, col1 + field3 AS col3 from core
                  

                  基本上,我只想使用别名,这样我就不需要执行之前执行的操作.这在mysql中可能吗?

                  Basically, I want to just use the alias so that I won't need to perform the operations performed earlier. Is this possible in mysql?

                  推荐答案

                  考虑使用子查询,例如:

                  Consider using a subquery, like:

                  SELECT col1
                  ,      col1 + field3 AS col3 
                  FROM   (
                         SELECT  field1 + field2 as col1
                         ,       field3
                         from    core
                         ) as SubQueryAlias
                  

                  这篇关于如何在 MySQL 中为字段或列设置别名?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!

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