Sails.js 与 postgreSQL 的一对多关联：列不存在

Question

我需要一些关于 sails 0.12.13 与 postgresql 关联的帮助。我有一个 "App" 模型和一个 "Membership" 模型。关系应该是一对多的（一个应用程序可以与许多关系相关联）。这是 App 模型数据库 table 架构（table 称为 "apps"）：

Table "public.apps"
   Column   |            Type             |                     Modifiers                     
------------+-----------------------------+---------------------------------------------------
 id         | integer                     | not null default nextval('apps_id_seq'::regclass)
 name       | character varying           | not null
Indexes:
    "apps_pkey" PRIMARY KEY, btree (id)
    "apps_name_key" UNIQUE CONSTRAINT, btree (name)
Referenced by:
    TABLE "memberships" CONSTRAINT "app_fk" FOREIGN KEY (app_id) REFERENCES apps(id) ON UPDATE RESTRICT ON DELETE CASCADE

这是会员资格：

Table "public.memberships"
   Column   |            Type             |                        Modifiers                         
------------+-----------------------------+----------------------------------------------------------
 id         | integer                     | not null default nextval('memberships_id_seq'::regclass)
 app_id     | integer                     | not null
Foreign-key constraints:
    "app_fk" FOREIGN KEY (app_id) REFERENCES apps(id) ON UPDATE RESTRICT ON DELETE CASCADE

在我的用户模型中，我有这个：

module.exports = {
  tableName: 'apps',
  autoCreatedAt: false,
  autoUpdatedAt: false,

  attributes: {
    name: { type: 'string', unique: true, required: true, alphanumericdashed: true },
    memberships: { collection: 'memberships', model: 'Membership' },
 }
}

这是会员模式：

module.exports = {
  tableName: 'memberships',
  autoCreatedAt: false,
  autoUpdatedAt: false,
  attributes: {
    app: { model: 'app', columnName: 'app_id' },
  },
};

当我尝试查询应用程序并获取其成员资格时：

App.find({ id: 1 }).populate('memberships').exec((err, app) => {
      if (err) throw err;

      console.log(app.memberships);
    });

我收到这个错误：

Error (E_UNKNOWN) :: Encountered an unexpected error
error: column apps.memberships does not exist
    at Connection.parseE (/usr/src/app/node_modules/sails-postgresql/node_modules/pg/lib/connection.js:539:11)
    at Connection.parseMessage (/usr/src/app/node_modules/sails-postgresql/node_modules/pg/lib/connection.js:366:17)
    at Socket.<anonymous> (/usr/src/app/node_modules/sails-postgresql/node_modules/pg/lib/connection.js:105:22)
    at emitOne (events.js:115:13)
    at Socket.emit (events.js:210:7)
    at addChunk (_stream_readable.js:252:12)
    at readableAddChunk (_stream_readable.js:239:11)
     at Socket.Readable.push (_stream_readable.js:197:10)
     at TCP.onread (net.js:589:20)

看起来关联不是 "enabled" 并且 waterline 正在我的模型中搜索实际列 "membership"。谁能解释我做错了什么？谢谢

Answer 1

根据documentation，我猜你的联想不好。

// App.js
module.exports = {
  tableName: 'apps',
  autoCreatedAt: false,
  autoUpdatedAt: false,

  attributes: {
    name: {
      type: 'string',
      unique: true,
      required: true,
      alphanumericdashed: true
    },
    memberships: {
      collection: 'membership', // <-- changed to singular (as your model should be)
      via: 'app'                // <-- use "via" instead of "model"
    },
  }
}

// Membership.js
module.exports = {
  tableName: 'memberships',
  autoCreatedAt: false,
  autoUpdatedAt: false,
  attributes: {
    app: {
      model: 'app'  
      // <-- removed the "columnName" here
    },
  },
};

此外，惯例通常说将您的模型命名为单个实例。例如，它是 "User.js" 而不是 "Users.js"。将集合称为复数是有效的。我对您的命名做了一些更改，但您必须看看这对您的文件有何影响（因为您没有提供这些名称）。

Sails.js 与 postgreSQL 的一对多关联：列不存在

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