MySQL如何连接两个字段上的表 [英] MySQL how to join tables on two fields

问题描述

我有两个带有 date 和 id 字段的表.我想加入这两个领域.我试过

I have two tables with date and id fields. I want to join on both fields. I tried

JOIN t2 ON CONCAT(t1.id, t1.date)=CONCAT(t2.id, t2.date)

可以，但是速度很慢.有没有更好的方法来做到这一点?

that works, but it is very slow. is there a better way to do this?

推荐答案

JOIN t2 ON t1.id=t2.id AND t1.date=t2.date

这篇关于MySQL如何连接两个字段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！