mysql或sql中有多少种连接类型 [英] how many types of joins are there in mysql or sql

问题描述

我听说有3种加入方式

我不确定确切的名字.谷歌搜索出现了各种术语，例如:

I'm not sure of the exact names. Googling has turned up a variety of terms like :

交叉联接，左联接，右联接，内部联接，外部联接，自联接....

Cross join , left join , right join , inner join , outer join, self join....

谁能告诉我MySQL中总共存在多少个联接.

Could anyone tell me how many joins exist in MySQL all in all.

推荐答案

联接是

1. Inner Join or Equi join
2. Self Join
2. Outer Join
   outer join is again classified into
   a) Left Outer Join
   b) Right Outer Join
   c) Full Outer Join
3. Cross join

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