SQL SQL中RIGHT＆LEFT JOIN与RIGHT＆LEFT OUTER JOIN之间的区别
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Difference between RIGHT & LEFT JOIN vs RIGHT & LEFT OUTER JOIN in SQL
提问by User 1034
What is the difference in results between:
结果之间的差异是什么：
- RIGHT JOIN and RIGHT OUTER JOIN
- LEFT JOIN and LEFT OUTER JOIN ?
- 右连接和右外连接
- 左连接和左外连接？
Can you please explain it through some examples?
你能通过一些例子来解释它吗？
回答by Pranay Rana
There is no difference between RIGHT JOINand RIGHT OUTER JOIN. Both are the same. That means that LEFT JOINand LEFT OUTER JOINare the same.
RIGHT JOIN和之间没有区别RIGHT OUTER JOIN。两者都是一样的。这意味着LEFT JOIN和LEFT OUTER JOIN是相同的。
回答by Leonard
Here's a very nice Visual Explanationof joins generally by our very own Jeff Atwood. A right outer join is the same as a right join, and left join and left outer join are also the same.
这是我们自己的 Jeff Atwood 对连接的非常好的视觉解释。右外连接与右连接相同，左连接和左外连接也相同。
回答by onedaywhen
What is result difference between:
RIGHT JOIN and RIGHT OUTER JOIN
什么是结果差异：
右连接和右外连接
No difference.
没有不同。
LEFT JOIN and LEFT OUTER JOIN ?
左连接和左外连接？
No difference.
没有不同。
Simply put, the OUTERkeyword is optional. You can include it or omit it without affecting the resultset.
简而言之，OUTER关键字是可选的。您可以包含或省略它而不影响结果集。
