'LEFT JOIN'vs'LEFT OUTER JOIN' [英] 'LEFT JOIN' vs 'LEFT OUTER JOIN'
本文介绍了'LEFT JOIN'vs'LEFT OUTER JOIN'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
我知道并没有什么区别，但是"LEFT JOIN"是ANSI形式，还是有任何RDBMS都将失败"LEFT JOIN"并要求"LEFT OUTER JOIN". [我在这里问是为了节省一些点击次数，填写表格等，以获得正确的ANSI标准！]
I know there is really no difference, but is 'LEFT JOIN' an ANSI form or are there any RDBMS's that will fail 'LEFT JOIN' and require 'LEFT OUTER JOIN'. [I am asking here so I can save a few clicks, form fillings, etc to get the correct ANSI standard!]
推荐答案
[OUTER] is optional, per the ANSI spec (92, but I'm sure later versions also cover it).
当然，您假设每个SQL产品都是ANSI兼容的.对于联接，它们可能是..
Of course, you're assuming that every SQL product is ANSI compatible. For joins, they probably are..
这篇关于'LEFT JOIN'vs'LEFT OUTER JOIN'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！
查看全文
