Sequelize 连接模型包括多对多

问题描述

假设我有三个这样的模型

Say I have three models like this

var User = _define('user', {
  username: Sequelize.INTEGER
});
var UserPubCrawl = _define('userpubcrawl', {
  user_id: Sequelize.STRING(64), // the user
  bar_id: Sequelize.INTEGER // 1 to many
});

var Bars = _define('bar', {
  name:  type: Sequelize.STRING,
}

感情是一顿饭

User(one) --> UserPubCrawl (to many) --> Bars(to many)

User(one) --> UserPubCrawl (to many) --> Bars(to many)

因此，1 个用户可以针对特定的 pub 爬网对许多条进行多次 pubcrawl我想找到辛普森"去过的所有酒吧.

So 1 user can have multiple pubcrawls to many bars for a particular pub crawlI want to find all the bars that "Simpson" went to.

我是否需要更改模型定义，如果需要，请告诉我?findAll 查询会是什么样子?

Do i need to change the model definitions, if so please show me?What would the findAll Query look like?

推荐答案

如果我理解你的数据库关系是正确的，它可以表述为:

If I understand your DB relationships right, it can be stated as:

1 个用户可以访问多个酒吧
1个酒吧可以被多个用户访问

1 user can visit many bars
1 bar can be visited by many users

因此，换句话说，用户和栏之间存在多对多关系，JOIN 表为 UserPubCrawl.

So, in other words you've a many to many relationship between Users and Bars, with the JOIN table being UserPubCrawl.

如果是这样，您的模型关联应如下所示:

If so, your model associations should look like:

User.belongsToMany(Bar, { through: UserPubCrawl });
Bar.belongsToMany(User, { through: UserPubCrawl });

而且，找出辛普森去过的所有酒吧，真的很简单:

And, finding out all the bars that Simpson went to, is really simple:

User.findAll({
  where: { user_id: '123' },
  include: {
    model: Bars,
    through: { attributes: [] } // this will remove the rows from the join table (i.e. 'UserPubCrawl table') in the result set
  }
});

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