猫鼬模式 [对象] 问题答案

【问题标题】：Mongoose Schema [Object] issue猫鼬模式 [对象] 问题
【发布时间】：2021-04-10 00:48:36
【问题描述】：

我正在使用通过 mongoose 连接到 mongoDB 的 Nodejs。需要在 Nodejs(Mongoose) 中应用以下工作聚合逻辑。聚合在 DB 端正常工作，但我收到 [Object] 错误。

模型 1 :getAllUsers

这里我不确定我的模型创建是否正确。

  var mongoose = require('mongoose');
    const getAllUsersDataSchema = new mongoose.Schema({
        
        userRefID:String ,
        userName:String,
        divisionId: String,
        divisionName:String,
        emailId :String,
//This role definition i created only for aggregation to work
        role:[{        
            userRefID:String,
            skillRefId:String,
            queueName:String,
           
        }]
    })
    module.exports = getAllUsers = mongoose.model('getAllUsers',getAllUsersDataSchema );

模型2 :getAllUsersRoles

var mongoose = require('mongoose');
const getAllUsersRolesDataSchema = new mongoose.Schema({   
    userRefID:String ,
    skillRefId: String,
    queueName:String,

})
module.exports = getAllUsersRoles = mongoose.model('getAllUsersRoles',getAllUsersRolesDataSchema);

数据库中的工作聚合查询：

     db.getallusers.aggregate([
...   {
...     "$lookup": {
...       "from": "getallusersroles",
...       "localField": "userRefID",
...       "foreignField": "userRefID",
...       "as": "role"
...     }
...   }
... ]).pretty()
{
        "_id" : ObjectId("5ff2b73d2af2b806685735a4"),
        "userRefID" : "07f426ff-506f-4e5e-afdb-2c7397edac61",
        "userName" : "EPS Purecloud Support",
        "divisionId" : "36852a81-ad7f-4c71-a1cd-7f431c05179f",
        "divisionName" : "",
        "emailId" : "eps@genesys.com",
        "role" : [
                {
                        "_id" : ObjectId("5ff2b73c2af2b8066857355f"),
                        "userRefID" : "07f426ff-506f-4e5e-afdb-2c7397edac61",
                        "skillRefId" : "c02dbb03-ed78-442a-a9cd-0f16c823646b",
                        "queueName" : "CIM_test",
                        "__v" : 0
                },
                {
                        "_id" : ObjectId("5ff2b73c2af2b80668573560"),
                        "userRefID" : "07f426ff-506f-4e5e-afdb-2c7397edac61",
                        "skillRefId" : "a626d99e-f5e9-47ab-a5d0-d493003c737f",
                        "queueName" : "CLAIMS",
                        "__v" : 0
                },       
               
        ],
        "__v" : 0
}

Nodejs 代码：

const express = require('express');
const router = express.Router();
const request = require('request');
const config = require('../config');
const fs = require('fs'); 
const getAllUsers = require ('../db/getAllUsersListmodel');
const getAllUsersRoles = require ('../db/getetUserRolesListModel');
var mongoose = require('mongoose');
mongoose.connect ('mongodb://localhost/testdb',{ useUnifiedTopology: true , useNewUrlParser: true });

router.get('/', (req, res) => {
   getAllUsers.aggregate([
      {
        "$lookup": {
          "from": "getallusersroles",
          "localField": "userRefID",
          "foreignField": "userRefID",
          "as": "role"
        }
      },
    
    ],(err,res)=>{
      console.log(res);
     
  })

});
  module.exports = router;

控制台输出错误：

 [
      {
        _id: 5ff2b73d2af2b806685735a4,
        userRefID: '07f426ff-506f-4e5e-afdb-2c7397edac61',
        userName: 'EPS Purecloud Support',
        divisionId: '36852a81-ad7f-4c71-a1cd-7f431c05179f',
        divisionName: '',
        emailId: 'eps@genesys.com',
        role: [ [Object], [Object] ],
        __v: 0
      },
    ]

【问题讨论】：

错误信息在哪里？附带说明一下，您应该将 Ref ID 存储为 ObjectId
另外，getAllUsersDataSchema 中的 role 字段是不必要的。 Aggregate 方法与 $lookup 不要求您的模型包含您的新输出字段。
嗨，Taf Rofe。即使我删除了 getAllUsersDataSchema 中的角色字段，我也会得到与 [Object] 相同的输出。你能帮我吗？谢谢
你应该尝试检查这些[Object]s。使用您当前的代码，您应该：console.log(res[0].role[0])

标签： javascript node.js mongodb mongoose aggregation-framework

【解决方案1】：

从你的代码中我可以理解：

这是User 型号：

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const UserSchema = new Schema({
    userName: {
        type: String,
    },
    divisionId: {
        type: Schema.Types.ObjectId,
    },
    divisionName: {
        type: String,
    },
    emailId: {
        type: Schema.Types.ObjectId,
    },
});

module.exports = getAllUsers = mongoose.model('User', UserSchema);

这是Role 型号：

const mongoose = require('mongoose');
const Schema = mongoose.Schema

const RoleSchema = new Schema({   
    userRefID: {
        type: Schema.Types.ObjectId,
    },
    skillRefId: {
        type: Schema.Types.ObjectId,
    },
    queueName: {
        type: String,
    },
});

module.exports = getAllUsersRoles = mongoose.model('Role', RoleSchema);

Aggregation 方法在起作用：

User.aggregate([
    {
      $lookup: {
        "from": "Role",
        "localField": "_id",
        "foreignField": "userRefID",
        "as": "roles"
      },
    },
]);

请用你的数据库完整数据试试这个。

还可以考虑使用mongoose.populate 来检索用户角色的结果：https://mongoosejs.com/docs/populate.html

【讨论】：