我听说有三种加入方式& E0 Z) F ^( t; T* _
我不确定确切的名字。谷歌搜索有各种术语,比如:' d" l" K1 X. ?, ~ s: R 交叉连接、左连接、右连接、内连接、外连接、自连接…。6 d5 I" A4 R. q0 v# T 谁能告诉我MySQL中共有多少个联系?$ N5 K* \1 U( O- r; ~. g0 q: u
^5 n% y8 L: o z5 u0 f% Z 解决方案: ! k4 e* p1 D# R 联接是9 d: t# ]' i! M; U6 _ C
1. Inner Join or Equi join2. Self Join2. Outer Join outer join is again classified into a) Left Outer Join b) Right Outer Join c) Full Outer Join3. Cross join