node.js - 尽管 MongoDB 中存在集合，Mongoose 显示空对象

Question

我尝试在 ExpressJS 应用程序中使用 mongoose 从本地 mongodb 获取数据。但无法获取数据。

我尝试使用 mongoose 和 mongojs 从 mongodb 检索数据。

甚至尝试在架构中传递正确的集合名称。

这是我的代码。

使用monogjs(blog.js)

var mongojs = require('mongojs');


      var db = mongojs('mongodb://localhost:27017/mydb', ['blogs']);

    // On Connection
    db.on('connect', function () {
    console.log('Mongo JS database connected')
    });
    //On Error
    db.on('error', function (err) {
    console.log('Mongo JS database error', err)
    });

    module.exports.getBlogs = function(res) {
    //var data = db.blogs.find();
    db.blogs.find({}, (rec, res)=>{
    if(rec){
      res.json(rec);
      console.log('Data '+ rec)
    }else{
      console.log('No Data '+ rec)
    }
    });
    }

使用 Mongoose (blogs.js)

----------------------
    const mongoose = require('mongoose');
    const config = require('../config/database');
    const DataSchema = mongoose.Schema ({
            "title": { type: String },
        "Description": { type: String },
        "Rate": { type: Number }
     }, { collection : 'Datas' });

    const Datas = module.exports = mongoose.model('Datas', DataSchema);
    //const Datas = module.exports = mongoose.model('Datas', DataSchema, 
    'Datas');

    module.exports.getblogs = function(){
    Data.find({}, (recs)=>{
        if(recs){
            console.log('Records found' + recs)
        }else{
            console.log('Records not found');
        }
    }); 

Answer 1

尝试给出下面的代码可能会起作用

在 Mongodb 集合中插入一条记录

const {MongoClient, ObjectID} = require('mongodb');//destructre the MongoClient object

var obj = new ObjectID();
console.log(obj);
const url  = "mongodb://localhost:27017/";
 var user ={name:'Prashant',Age:22};
 var {name}=user ; //destructre the user object
 console.log(name);
 MongoClient.connect(url,function(err,db){
   if(err) throw err;
   var dbo=db.db("TodoApp");
   var myobj ={
     name:"Prashant",
     address:"kanpur",
     Age:22,
     Work:"Accord"
   };
   dbo.collection("user").insertOne(myobj,function(err,res){
     if(err) throw err;
     console.log(res.ops[0]._id.getTimestamp());
     db.close();
   });
 });

从 Mongodb 集合中获取一条记录。

const {mongoose}= require('./../server/db/mongoose');
const {Todo} = require('./../server/models/todo');
const {ObjectID} = require('mongodb');
const {User}    = require('./../server/models/user');
var id= '5b13960c4730b43f80cef6af';

if(!ObjectID.isValid(id)){
  console.log('Id not valid');
};

Todo.find({
  _id: id
}).then((todos)=>{
  console.log('Tdod',todos);
});

Todo.findOne({
  _id: id
}).then((todo)=>{
  console.log('Todo',todo);
});