Oracle中的双表是什么? [英] What is the dual table in Oracle?

问题描述

我听见有人提到这张桌子，但不确定它是关于什么的.

I've heard people referring to this table and was not sure what it was about.

推荐答案

这是一种虚拟表，具有一条记录，用于选择何时您实际上对数据不感兴趣，而是想要某些系统函数的结果在选择语句中:

It's a sort of dummy table with a single record used for selecting when you're not actually interested in the data, but instead want the results of some system function in a select statement:

例如select sysdate from dual;

请参见 http://www.adp-gmbh.ch/ora/misc /dual.html

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