Sails.js 模型：创建 2 个与自身的关联失败

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'user'本身的关联。

我的问题是当模型只有 1 个关联时，无论是关注者还是关注者，它都有效。但是follower和following都包含的时候会报错

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'
   }
}

代码会出现这样的错误：

    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 follower，另一侧是 following，反之亦然。换句话说：

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

您可以在以下网址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

Sails.js 模型：创建 2 个与自身的关联失败

Sails.js Model: create 2 association to self failed

node.js

sails.js

waterline

sails-mongo