本文介绍了确定Oracle null == null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小编来一起学习吧！
问题描述
我希望在可为空的列上搜索数据库表.有时，我要搜索的值本身就是NULL.因为Null等于零，甚至NULL，所以
I wish to search a database table on a nullable column. Sometimes the value I'm search for is itself NULL. Since Null is equal to nothing, even NULL, saying
where MYCOLUMN=SEARCHVALUE
将失败.现在我必须求助于
will fail. Right now I have to resort to
where ((MYCOLUMN=SEARCHVALUE) OR (MYCOLUMN is NULL and SEARCHVALUE is NULL))
有一种更简单的说法吗?
Is there a simpler way of saying that?
(如果重要的话，我正在使用Oracle)
(I'm using Oracle if that matters)
推荐答案
您可以执行IsNull或NVL任务，但这只会使引擎做更多的工作.您将调用函数进行列转换，然后必须将结果进行比较.
You can do the IsNull or NVL stuff, but it's just going to make the engine do more work. You'll be calling functions to do column conversions which then have to have the results compared.
使用现有的东西
where ((MYCOLUMN=SEARCHVALUE) OR (MYCOLUMN is NULL and SEARCHVALUE is NULL))
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