蓝鸟承诺猫鼬组由

Question

我有一个猫鼬模型

'use strict';

var mongoose = require('bluebird').promisifyAll(require('mongoose'));
var Schema = mongoose.Schema;

function toLower (v) {
  return v.toLowerCase();
}

var Signup = new Schema({
  name: { type: String, required: true },
  email: { type: String, unique: true, required: true, set: toLower },
  position: { type: String },
  area: String,
  companySize: Number,
  created: { type: Date, default: Date.now }
});

module.exports = mongoose.model('Signup', Signup);

我想按创建（日期格式为天）分组并计算 _id 的数量。

我是猫鼬和蓝鸟的新手……谁能给我举个例子？谢谢！！！

Answer 1

我设法得到了我想要的：

SignupModel
  .aggregate([
    {
      $group: {
        _id: { $week: "$created" },
        "count": { "$sum": 1 }
      }
    }
  ])
  .execAsync()
  .then(responseWithResult(res))
  .catch(handleError(res));

=> 按创建（周）分组并求和