如何在Oracle中将两列的比较选择为一列 [英] How to select the comparison of two columns as one column in Oracle

问题描述

我无法弄清楚如何在我的SELECT查询中添加一列，以指示两列在Oracle中是否包含相同的数据.

I cannot figure out how to add a column to my SELECT query indicating whether two columns contain the same data in Oracle.

我想编写一个查询，例如:

I would like to write a query like:

select column1, column2, column1=column2 from table

，如果我有这张桌子:

+---------+---------+
| column1 | column2 |
+---------+---------+
| value1  | value1  |
| value2  | value3  |
| value4  | value4  |
+---------+---------+

得到类似的结果

+---------+---------+-----------------+
| column1 | column2 | column1=column2 |
+---------+---------+-----------------+
| value1  | value1  | true            |
| value2  | value3  | false           |
| value4  | value4  | true            |
+---------+---------+-----------------+

正确的语法是什么?

推荐答案

如果您也想考虑null值的相等性，请尝试以下操作

If you want to consider null values equality too, try the following

select column1, column2, 
   case
      when column1 is NULL and column2 is NULL then 'true'  
      when column1=column2 then 'true' 
      else 'false' 
   end 
from table;

这篇关于如何在Oracle中将两列的比较选择为一列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IT屋！