SQL Inner连接两个以上的表 [英] SQL Inner join more than two tables

问题描述

我现在可以通过以下方式查询关于外键/主键是否相等的两个表的联接.

I can currently query the join of two tables on the equality of a foreign/primary key in the following way.

 $result = mysql_query("SELECT * FROM `table1` 
                         INNER JOIN 
                       `table2` ON table1.primaryKey=table2.table1Id");

我想将此扩展到多个表(所有表都具有相同的外键).我正在尝试下面的代码，该代码不返回任何内容.谁能指出我做错了什么?

I'd like to extend this to multiple tables (all with the same foreign keys). I am trying the following code which is not returning anything. Can anyone point out what I'm doing wrong?

 $result = mysql_query("SELECT * FROM `table1` 
                        INNER JOIN `table2` 
                        INNER JOIN table3 
                        ON table1.primaryKey=table2.table1Id=table3.table1Id");

推荐答案

SELECT * 
FROM table1 
INNER JOIN table2
      ON table1.primaryKey=table2.table1Id
INNER JOIN table3
      ON table1.primaryKey=table3.table1Id

这篇关于SQL Inner连接两个以上的表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！