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mysql-MySQL联接查询到的显示结果

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Jun 06, 2016 am 09:41 AM

mysqlselect联接查询数据库

表：fruits的字段f_id为primary key
图片说明
表：suppliers的字段s_id为primary key与fruits的s_id有相同的数据类型

然后使用这2句查询语句：
1、select suppliers.s_id,s_name,f_name,f_price from suppliers inner join fruits on suppliers.s_id=fruits.s_id;
查询的都结果如下：

2、select suppliers.s_id,s_name,f_name,f_price from fruits inner join suppliers on fruits.s_id=suppliers.s_id;
查询到的结果如下：
图片说明

可以确定的是查询的结果肯定是一样的，但是问题是使用第一句查询语句的条件是suppliers.s_id=fruit.s_id，我的理解是，当我们连接两张检索数据的时候，检索的方式是首先逐行扫描suppliers表中s_id的记录，只有条件suppliers.s_id=fruit.s_id匹配，结果才会被检索出来，所以首先要从表suppliers的s_id匹配表fruits的s_id的相等项，按道理说第一句查询语句查询到的结果应该是按照表suppliers的s_id顺序显示，为什么两个查询语句的显示结果的都是按照friuts本身的s_id的排列顺序？

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