风帆模型查询

Question

我有 3 个模型（房间、模块和设备）：房间：

/**
 * Room.js
 *
 * @description :: TODO: You might write a short summary of how this model works and what it represents here.
 * @docs        :: http://sailsjs.org/#!documentation/models
 */

module.exports = {

  attributes   : {
    name    : {
      type     : 'string',
      required : true
    },
    image   : {
      type : 'binary'
    },
    modules : {
      collection : 'Module',
      via        : 'inRoom'
    },
    toJSON  : function ()
    {
      var obj = this.toObject();
      if (obj.image)
      {
        var base64data = new Buffer(obj.image.toString(), 'binary').toString();
        obj.image = base64data;
      }
      return obj;
    }
  },
  beforeCreate : function (attrs, next)
  {
    next();
  }
  ,
  beforeUpdate : function (attrs, next)
  {
    next();
  }
}
;

模块：

/**
 * Module.js
 *
 * @description :: TODO: You might write a short summary of how this model works and what it represents here.
 * @docs        :: http://sailsjs.org/#!documentation/models
 */

module.exports = {

  attributes : {
    name      : {
      type     : 'string',
      required : true
    },
    nbDevices : {
      type       : 'integer',
      defaultsTo : 1
    },
    image     : {
      type : 'binary'
    },
    inRoom    : {
      model : 'Room'
    },
    devices   : {
      collection : 'Device',
      via        : 'module'
    }
  }
};

设备：

/**
 * Device.js
 *
 * @description :: TODO: You might write a short summary of how this model works and what it represents here.
 * @docs        :: http://sailsjs.org/#!documentation/models
 */

module.exports = {

  attributes : {
    name   : {
      type     : 'string',
      required : true
    },
    index  : {
      type       : 'integer',
      defaultsTo : 0
    },
    value  : {
      type       : 'integer',
      defaultsTo : 0
    },
    image  : {
      type : 'binary'
    },
    module : {
      model : 'Module'
    }
  }
};

我想取回我所有的房间，里面有所有的设备。现在我喜欢这样：

Room.find().populate('modules')
      .exec(function (err, rooms)
      {
        var index = 0;
        var total = rooms.length-1;
        _(rooms).forEach(function (room)
        {
          Device.find({module : _.pluck(room.modules, 'id')}).populate("module").exec(function (err, data)
          {
            room.devices = data;
            console.log(room);
            if(total == index)
            {
              return res.json(rooms);

            }
            index++;
          });
        }).value();

      });

但它看起来不像 clean/safe 方法。还有另一种方法可以实现这一目标吗？我看到这个 post Sails.js populate nested associations 但无法使用 find 而不是 findOne。

Answer 1

您可以使用您在回答中提到的 async or some other library for control flow to add to the example 来执行以下操作：

var async = require('async');

Room.find()
.populate('modules')
.exec(function (err, rooms) {
    // if(err) ...

    async.forEach(room,
        // apply on each room
        function(room, cb){
            if(err || !room) return cb(err);

            Device.find({module : _.pluck(room.modules, 'id')})
            .populate("module")
            .exec(function(err, devices){
                room.devices = devices;
                cb();
            });

        },
        // when all rooms are done
        function(err){
            // if(err) ...
            res.json(rooms);
        }
    );
});

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