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
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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;
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