这种情况mysql 怎么建表比较好
这种情况mysql 如何建表比较好
条件：一个用户可以订阅多种邮件
需要的功能如下：
我查询一个用户 可以得出这个用户订阅的邮件种类
我查询一个邮件种类 可以得出哪些用户订阅了此邮件
这样子的话 如何建表比较合适
我的想法是建一个用户订阅表 和邮件表
用户订阅表中 一个字段 存 这个用户所有订阅的邮件ID
但是这样子有个问题
我查这个用户，可以方便知道这个用户订阅的种类
查一个邮件种类的话，查询哪些用户订阅了此邮件就比较麻烦了
大家有没有好的建表想法呢
------解决方案--------------------
可以建立3个表;
1个用户表;
一个邮件种类表;
在一个用户订阅邮件记录表；
这样操作起来和扩展起来都比较方便
------解决方案--------------------
三个表：
用户表、邮件表 和 用户订阅表
前两个你知道的
用户订阅表 有 用户id 和 邮件id 两个字段
从字段名就应该知道怎么做了
------解决方案--------------------
查询种类可以用模糊查询、正则或其他方法啊
不然如果有10万个种类（这不算大数目，新闻组比这还多）怎么办？
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