PL/SQL“在x和y之间"如果y< X.为什么? [英] PL/SQL "between x and y" does not work, if y < x. Why?

问题描述

我有一个PL/SQL代码，例如:

I have a PL/SQL code like:

case when column between 201203 and 201201
then other_column
end

我知道列中的值为201203.因此代码应返回一些值.直到我像这样纠正它时才这样:

I know that there are values in column that are 201203. So code should return some values. But it didn't until I corrected it like:

case when column between 201201 and 201203
then other_column
end

为什么关键字之间的效果如此?如何在Oracle数据库上实现它?

Why between keyword works like that? How it is implemented on Oracle Databases?

推荐答案

这是ANSI SQL行为.

This is ANSI SQL behavior.

 expr1 BETWEEN expr2 AND expr3

翻译为

 expr2 <= expr1 AND expr1 <= expr3

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