node.js - Sails.js 模型 : create 2 association to self failed

Question

我对 Nodejs 和 sails 还很陌生。我正在实现一个类似于 Twitter 的服务器。在用户模型中，应该有2个字段:follower和following，这2个字段是模型“用户”本身的关联。

我的问题是，当模型只有 1 个关联(关注者或关注者)时，它会起作用。但是当follower和following都包含时，就会报错。

代码是这样的:

module.exports = {
   attributes: {
   alias: {
     type:'string',
     required: true,
     primaryKey: true
   },
   pwd: {
    type: 'string',
    required: true
   },
   follower: {
      collection: 'user',
      via: 'alias'
   },
   following:{
      collection: 'user',
      via: 'alias'
   }
}

代码会导致这样的错误:

    usr/local/lib/node_modules/sails/node_modules/waterline/node_modules/waterline-schema/lib/waterline-schema/references.js:115
throw new Error('Trying to associate a collection attribute to a model tha
      ^
Error: Trying to associate a collection attribute to a model that doesn't have a Foreign Key. user is trying to reference a foreign key in user
at References.findReference (/usr/local/lib/node_modules/sails/node_modules/waterline/node_modules/waterline-schema/lib/waterline-schema/references.js:115:11)
at References.addKeys (/usr/local/lib/node_modules/sails/node_modules/waterline/node_modules/waterline-schema/lib/waterline-schema/references.js:72:22)

Answer 1

对于这种用法，您的模型定义不正确，即 via 关键字。根据waterline associations docs via 关键字引用关联的另一端。因此，对于追随者来说，另一方是跟随，反之亦然。换句话说:

follower: {
  collection: 'user',
  via: 'following'
},
following:{
  collection: 'user',
  via: 'follower'
}

您可以在以下位置查看完整的工作示例:https://github.com/appscot/sails-orientdb/blob/master/test/integration-orientdb/tests/associations/manyToMany.selfReferencing.js