无法从 Web 应用程序的 MongoDB 数据库中获取数据

Question

我是使用 MongoDB 的新手。目前，我正在制作一个需要一些数据存储的 Web 应用程序。我在 Node.js 上建立了一个 HTTP 服务器，它在 localhost:3000 上运行。我还使用 Vagrant 和 VirtualBox 构建了一个虚拟开发环境。我正在从 PuTTy 访问 Mongo shell（如果这完全相关的话）。在合并 MongoDB 之前，它运行良好，因为我将数据存储在 Node.js 程序内存中。

此网络应用程序是一个在线待办事项列表。我遇到的第一个错误是 get 路线。我已插入 Mongo 数据库的“待办事项”列表不会出现在 localhost 的站点上。它似乎没有从数据库中获取数据。我得到的第二个错误是 post 路线。当我通过本地主机上的用户界面插入“待办事项”并刷新页面时，本地主机上的待办事项列表会更新为特定的待办事项（但不是我插入数据库中的待办事项）。但是，它似乎没有将其添加到数据库中，并且我仍然在控制台上收到此错误：

vagrant@precise32:~/app$ node server.js
{ description: 'descTest3', tags: [ 'tagTest3' ] }
Mongoose: mpromise (mongoose's default promise library) is deprecated, plug in your own promise library instead: http://mongoosejs.com/docs/promises.html 

我不确定为什么会出现这个错误，因为我似乎没有使用任何承诺。

server.js

var express = require("express"), http = require("http"), app = express(), mongoose = require("mongoose");

app.use(express.static(__dirname + "/client"));

app.use(express.urlencoded());

mongoose.connect('mongodb://localhost/WatNext');//connect to the WatNext data store in mongoDB

var ToDoSchema = mongoose.Schema({ 
    "description": String,
    "tags": [ String ] //array of Strings
});

var ToDo = mongoose.model("ToDo", ToDoSchema)

http.createServer(app).listen(3000);
//get and post routes:

app.get("/toDos.json", function (req, res) {
    ToDo.find({}, function (err, toDos) {
        if (err != null){
            console.log(err);
        }
        res.json(toDos);
    });
});

app.post("/todos", function (req, res) {
    console.log(req.body);
    var addedToDo = new ToDo({"description" : req.body.description, "tags" : req.body.tags});
    //save function saves object into the database
    addedToDo.save(function (err, result) {
        if (err != null){//if there is an error
            console.log(err);
            res.send("ERROR SAVING");
        }
        else {
            ToDo.find({}, function (err, result) {
                if (err != null){//if there is an error in finding
                    res.send("ERROR FINDING");
                } 
                res.json(result);
            }); 
        }
    });
});

app.js

var main = function (toDoObjects) {
//do stuff with ToDoObjects including outputting the list of ToDos
};
$(document).ready(function() {
    $.getJSON("toDos.json", function(toDoObjects) {
        main(toDoObjects);
    })
});

mongo shell

> show dbs
WatNext 0.0625GB
local   0.03125GB
> use WatNext
switched to db WatNext
> show collections;
system.indexes
toDoCollection
todos
> db.toDoCollection.find();
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf1"), "description" : "Get groceries and eat afterwards", "tags" : [  "shopping",  "chores" ] }
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf2"), "description" : "Make up some new To-Dos", "tags" : [  "writing",  "work" ] }
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf3"), "description" : "Prep for Monday's class", "tags" : [  "work",  "teaching" ] }
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf4"), "description" : "Answer emails", "tags" : [  "work" ] }
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf5"), "description" : "Take April to the park", "tags" : [  "chores",  "pets" ] }
{ "_id" : ObjectId("58b38dd8fb355f57162d9cf6"), "description" : "Finish writing this book", "tags" : [  "writing",  "work" ] }

编辑： 我发现这只是命名错误。

我也发现了

mongoose.Promise = require("bluebird");

解决了 promise 错误的问题。不过记得先安装模块：

npm install --save bluebird

Answer 1

我发现出了什么问题。这是 GET 和 POST 路由的命名错误。应该是：

app.get("/todos.json", function (req, res) { //get the data from the collection called 'todos' in MongoDB

还有：

$.getJSON("todos.json", function(toDoObjects) {

我应该使用todos 集合而不是toDoCollection：

 "description" : "descTest1", "_id" : ObjectId("58b39a1fb1a30305075408fa"), "tags" : [  "tagTest2" ], "__v" : 0 }
{ "description" : "descTest2", "_id" : ObjectId("58b4c837d47a5604c7c0609a"), "tags" : [  "tagsTest2" ], "__v" : 0 }
{ "description" : "descTest3", "_id" : ObjectId("58b4ca0491f4c804d200cda9"), "tags" : [  "tagTest3" ], "__v" : 0 }
{ "description" : "descTest4", "_id" : ObjectId("58b4e636b71d0a05ebb7a71a"), "tags" : [  "tagTest4" ], "__v" : 0 }
{ "description" : "descTest5", "_id" : ObjectId("58b60211428520053a4714ed"), "tags" : [  "tagTest5" ], "__v" : 0 }
{ "_id" : ObjectId("58b6037839e65d96e13cf68e"), "description" : "descTestMONGO", "tags" : [  "tagTestMONGO" ] }
{ "_id" : ObjectId("58b605b339e65d96e13cf690"), "description" : "Take April to the park", "tags" : [  "chores",  "pets" ] }