從三個表準備報告

Question

我要準備從三個表中的報告在php中。 作爲表A的主鍵是表B的外鍵和表B的主鍵是表C中的外鍵，現在要去從表C和表A中選擇數據。表A和表C不直接相關彼此

Answer 1

嘗試以下查詢：

select * from A 
inner join B on A.primary_key = B.Foreign_key 
inner join C on B.primary_key = C.foreign_key 

Here A.primary_key = A's primary key 
Here B.Foreign_key = A's primary key in B's table 
B.primary_key = B's primary key 
C.foreign_key = B's primary key in C's table