MySQL 中逗号分隔的连接和语法上的连接有什么区别? [英] What's the difference between comma separated joins and join on syntax in MySQL?

查看:31
本文介绍了MySQL 中逗号分隔的连接和语法上的连接有什么区别?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

例如,如果我有一个表Person",其中一个id"列引用了Worker"表中的id"列

For example if I were to have a table "Person" with a column "id" that references a column "id" in table "Worker"

这两个查询之间的区别是什么?它们产生相同的结果.

What would the difference between these two queries be? They yield the same results.

SELECT * 
FROM Person 
JOIN Worker 
  ON Person.id = Worker.id;

SELECT * 
FROM Person, 
     Worker 
WHERE Person.id = Worker.id;

谢谢

推荐答案

完全没有区别.

第一种表示使查询更具可读性,并且可以很清楚地看出哪个连接对应哪个条件.

First representation makes query more readable and makes it look very clear as to which join corresponds to which condition.

这篇关于MySQL 中逗号分隔的连接和语法上的连接有什么区别?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!

查看全文
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆