How can we differ LEFT OUTER JOIN vs Left Join [duplicate]

问题

This question already has answers here:

LEFT JOIN vs. LEFT OUTER JOIN in SQL Server (12 answers)

Closed 4 years ago.

What is the difference between Left Join and Left Outer Join?

回答1:

They are the same thing in MySQL. A LEFT JOIN is a synonym or shorthand for LEFT OUTER JOIN.

回答2:

There is none. The keyword OUTER is optional. They mean the same.

来源：https://stackoverflow.com/questions/2809594/how-can-we-differ-left-outer-join-vs-left-join