Why am I keeping getting 'Collection is undefined' error on MongoDb - javascript

I tried to connect to my db but it keep on returning that the collection is undefined even though I already declared it as a global variable. Not really sure what the closure issue is.
const express = require('express');
const app = express();
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
let db;
MongoClient.connect('mongodb://localhost:27017/todos', { useUnifiedTopology: true }, (err, client) => {
assert.equal(nul, err);
db = client.db('todos');
db.collection('todos').insertMany([
{ done:true, desc: 'write code'},
{ done:true, desc: 'write code'},
{ done:true, desc: 'write code'},
]);
client.close();
})
app.get('/', (req, res) => {
res.json('did this work!');
});
app.get('/todos', async (req, res) => {
const todos = await db.collection('todos').find().toArray();
res.json(todos);
});
app.listen(3001, () =>{
console.log("work pls");
});

Related

Firebase functions can't access my middleware routes

///index.js
const functions = require("firebase-functions");
const express = require("express");
const app = express();
const productRouter = require('./routes/productRoutes');
const globalErrorHandler = require('./controllers/errorController');
const AppError = require('./utils/appError');
// Compressing upcompressed files which is been sent to client such text.
if (process.env.NODE_ENV === 'development') {
app.use(morgan('dev'));
}
// app.use(express.static(path.join(__dirname, 'public')));
app.get('/', (req, res) => {
res.send('Hello World')
});
app.get('/homepage', (req, res) => {
res.send('Hello People of God')
});
app.use('/products', productRouter);
// Handing Unhandled Routes
app.all('*', (req, res, next) => {
next(new AppError(`Can't find ${req.originalUrl} on this server!`, 404));
});
app.use(globalErrorHandler);
exports.app = functions.https.onRequest(app);
///productRoutes.js
const express = require('express');
const {
getProduct,
getAllProduct,
} = require('./../controllers/productController');
const router = express.Router();
router
.route('/')
.get(getAllProduct);
router
.route('/:id')
.get(getProduct);
module.exports = router;
///productController.js
const AppError = require('../utils/appError');
const Product = require('../modals/productModels');
const catchAsync = require('../utils/catchAsync');
// GET SINGLE PRODUCT CONTROLLER
exports.getProduct = catchAsync(async (req, res, next) => {
const product = await Product.findById(req.params.id)
.populate('reviews');
if (!product) {
return next(new AppError('No product found with that ID', 404));
}
res.status(200).json({
status: 'success',
data: {
product
}
});
});
// GET ALL PRODUCT CONTROLLER
exports.getAllProduct = catchAsync(async (req, res, next) => {
const products = await Product.find();
res.status(200).json({
status: 'success',
results: products.length,
data: {
products
}
});
});
///server.js
const mongoose = require('mongoose');
const app = require('./index')
const dotenv = require('dotenv');
// CONNECTING TO MONGODB SERVER
dotenv.config({ path: './config.env' })
const DB = process.env.DATABASE.replace('<PASSWORD>', process.env.DATABASE_PASSWORD);
mongoose.connect(DB, {
useNewUrlParser: true,
safe: true,
strict: false,
useUnifiedTopology: true
}).then(con => console.log('DB connection successful'))
const port = process.env.PORT || 3000;
app.listen(port, () => {
console.log(`App running on port ${port}...`);
});
After running function serve on my terminal i can access the two '/' and 'homepage' app.get which return the res "Hello world" and "Hello people of God" but can't access app.use('/products', productRouter). Its does take some time to run and throw an error "{"code":"ECONNRESET"}" please why is this so.
Am expecting to get my list of products from my mongodb data base.

How can we add collections in mongoDB dynamically( through users)?

Adding collections manually is easy but adding it dynamically giving me unexpected answer.
I am getting a collection name from frontend to backend using promt and axios but when I am doing
const variable_from_frontEnd = mongoose.model(variable_from_frontEnd, Schema);
it is not adding any collections.
import express from "express";
import mongoose from "mongoose";
import Messages from "./messages.js";
import cors from "cors";
// app configuration
const app = express();
const port = process.env.PORT || 9000;
const pusher = new Pusher({
appId: "1183689",
key: "c9fa659fc6b359a23989",
secret: "9da56a5db535e10c7d95",
cluster: "eu",
useTLS: true
});
//middleware
app.use(express.json());
app.use(cors());
// DB Configuration
const url = "mongodb+srv://suraj_bisht_99:zoe6B82AZjaLXgw7#cluster0.zp9dc.mongodb.net/Whatsapp_MERN?retryWrites=true&w=majority";
mongoose.connect(url, {useCreateIndex: true, useNewUrlParser: true, useUnifiedTopology: true})
.then(()=> console.log('mongoDB is connected'))
.then(err => console.log(err));
const groupSchema = mongoose.Schema( {
message: String,
name: String,
timestamp: String,
received: Boolean,
});
// API routes
app.get("/", (req, res) => {
res.status(200).send("Hello World");
})
app.get("/messages/sync", async (req, res) => {
await Messages.find( (err, data) => {
if(err){
console.log(err);
res.status(500).send(err);
}else{
res.status(200).send(data);
}
})
})
app.post("/messages/new", async (req, res) => {
try{
const newMessage = new personalGroup(req.body);
const newMessageCreated = await newMessage.save();
res.status(201).send(newMessageCreated);
}
catch(err){
res.status(400).send(err);
}
});
// route for creating new collection in mongoDB
app.post("/room/new", async (req, res) => {
try{
let groupName = req.body.room;
groupName = mongoose.model(groupName, groupSchema);
if(!groupName){
console.log("error is occured");
}else{
console.log(groupName);
}
}
catch(err){
res.status(400).send(err);
}
})
// listening part
app.listen(port, () => console.log(`listening on port number ${port}`));
Let's say I have type a collection name "studyGroup" from frontend then
console is giving me
Model { studyGroup }
Can someone help me why it is happening and how can I add collections manually.

MongoDB Returns Empty Error Object when Making POST Request

I'm currently learning about APIs. I'm using Dev Ed's video on a RESTful MERN API. I set up my routes and I could successfully connect to my MongoDB database. However, when attempting to call save() on a post to the DB, I was returned my error message, a JSON object with a message containing the err, but my err object was completely empty.
posts.js:
const express = require('express');
const router = express.Router();
const Post = require('../models/Post');
router.get('/', (req, res) => {
res.send('We are on /posts!');
});
router.post('/', (req, res) => {
const post = new Post({
title: req.body.title,
desc: req.body.desc,
});
post.save()
.then(data => {
res.json(data);
})
.catch(err => {
res.json({ message: err });
});
});
module.exports = router;
app.js:
const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
require('dotenv/config');
const app = express();
const PORT = 8080;
app.use(bodyParser.json());
// Import Routes ------------------------
const postsRoute = require('./routes/posts');
app.use('/posts', postsRoute);
// ROUTES --------------------------------
app.get('/', (req, res) => {
res.send('We are home!');
});
mongoose.connect(
process.env.DB_CONN,
{ useNewUrlParser: true },
() => {
console.log('Succesfully connected to DB!')
});
app.listen(PORT);
Post.js (schema):
const mongoose = require('mongoose');
const PostSchema = mongoose.Schema({
title: {
type: String,
required: true,
},
desc: {
type: String,
required: true,
},
date: {
type: Date,
default: Date.now,
}
});
module.exports = mongoose.model('Posts', PostSchema);
My POST request and response (Postman):
In my code, I am attempting to send the new Post to my DB, but instead I get an error, an empty one. I either need to figure out how to view my error correctly (so that's it's not empty) or the larger problem: why my POST request is failing.
Again, I am learning about APIs, this is my very first time writing one. If there's anything I missed (like other code that you would need) or if there's something I should be doing differently, please, let me know! Thank you in advance!
use status when you want to use res like this:
for success result
res.status(200).json(data);
for .catch
res.status(500).json({ message: err });
but I prefer use async/await with try/cacth like this:
router.post('/', async(req, res) => {
const post = new Post({
title: req.body.title,
desc: req.body.desc,
});
try {
let data = await post.save()
res.status(200).json(data)
} catch (error) {
res.status(500).json({ message: error});
}
});
check the documentation of promises in mongnoos
check the connection of mongoose like this:
const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');
require('dotenv/config');
const app = express();
const PORT = 8080;
app.use(bodyParser.json());
// Import Routes ------------------------
const postsRoute = require('./routes/posts');
app.use('/posts', postsRoute);
// ROUTES --------------------------------
app.get('/', (req, res) => {
res.send('We are home!');
});
runMongoose()
app.listen(PORT);
async function runMongoose(){
try {
await mongoose.connect(
process.env.DB_CONN,
{ useNewUrlParser: true }
);
console.log("mongodb is OK");
} catch (error) {
console.log("mongodb Warning", error);
}
}
if Succesfully connected to DB! printed mongoose connection is OK
the problem is that you added
{ useNewUrlParser: true }
remove that and it's gonna work fine ;)

node.js req.body returning undefined

EDIT: #LawrenceCherone solved this, its (req, res, next) not (err, res, req)
I am creating a MERN app (Mongo, express, react, node).
I have some routes that work fine and return data from mongodb. However I created a new controller to access a separate collection and whenever i try to create a new document in it my req.body returns undefined.
I have setup my server.js like this:
const express = require("express");
const bodyParser = require("body-parser");
const cors = require("cors");
const connectDB = require("./db");
const app = express();
const apiPort = 3000;
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cors());
app.use(bodyParser.json());
connectDB();
app.use("/api", require("./routes/router"));
var server = app.listen(apiPort, () => console.log(`Server running on port ${apiPort}`));
module.exports = server;
My router looks like this:
const express = require("express");
const QuizController = require("../controllers/quiz-controller");
const UserController = require("../controllers/user-controller");
const router = express.Router();
// quiz routes
router.post("/quizzes", QuizController.createQuestion);
router.get("/quizzes", QuizController.getAllQuestions);
router.get("/quizzes/:quiz_name", QuizController.getQuestionsByQuiz);
router.get("/quizzes/questions/:question_id", QuizController.getQuestionById);
router.put("/quizzes/:question_id/edit", QuizController.updateQuestionById);
router.delete("/quizzes/:question_id", QuizController.deleteQuestionById);
// user routes
router.post("/users", UserController.createUser);
module.exports = router;
All of the /quizzes routes work perfectly fine and i have had no trouble accessing the body. The UserController.createUser method is almost identical to Quizcontroller.createQuestion too so I am very confused.
Here is the user-controller with the createUser function:
const User = require("../models/User");
createUser = async (err, res, req) => {
const body = req.body;
console.log(req.body);
console.log(req.params);
console.log(body);
if (!body) {
return res.status(400).json({
succes: false,
error: "You must provide a body",
});
}
try {
const newUser = new User(body);
console.log(newUser);
if (!newUser) {
return res.status(400).json({ success: false, error: err });
}
const user = await newUser.save();
return res
.status(200)
.json({ success: true, newUser: user, msg: "New user created" });
} catch (err) {
console.error(err.message);
res.status(500).send("Server error");
}
};
module.exports = { createUser };
Here is an image of the postman request I am using to try test this:
[1]: https://i.stack.imgur.com/UHAK5.png
And the user model:
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const UserSchema = new Schema({
name: {
type: String,
required: true,
},
emailAddress: {
type: String,
required: true,
},
permission: {
type: String,
required: true,
},
auth0Id: {
type: String,
required: true,
},
});
module.exports = mongoose.model("users", UserSchema);
The functional parameter order matters.
its
createUser = async (req, res, next) => // correct format
Not
createUser = async (err, res, req) // wrong format

find function is not working in mongoose with specified field

So I am making this website where you can see different recipes for food. When browsing for recipes, I want the user to be able to select a category and browse all the dishes that fall under it (i.e dessert, dinner, vegan etc).
I have this function I created in my router file that returns all the dishes that fall under the specified category:
router.get('/showrecipes/:categoryname', (req, res, next) => {
let nameQuery = {category: req.params.categoryname};
Recipe.find(nameQuery, (err, recipes) => {
if (err) throw err;
res.json(recipes);
});
});
However, when I try to test it out in Postman, I keep getting Null instead of all the dishes that fall under the category.
All my other functions are correctly working, but this one seems to have issues.
For reference, here is the rest of the recipeRouter file:
const express = require('express');
const passport = require('passport');
const Recipe = require('../models/recipe');
const jwt = require('jsonwebtoken');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
router = express.Router();
router.get('/', (req, res, next) => {
res.json('Here are the recipes!')
});
// Is working
router.get('/showrecipes', (req, res, next) => {
Recipe.find({}, (err, recipes) => {
if (err) throw err;
res.json(recipes);
});
});
// Is working.
router.get("/showrecipes/:recipename", (req, res, next) => {
let nameQuery = {name: req.params.recipename};
Recipe.findOne(nameQuery, (err, recipes) => {
if (err) throw err;
res.json(recipes);
})
});
// Is not crashing, but is returning Null which isn't how it's supposed to work.
router.get('/showrecipes/:categoryname', (req, res, next) => {
let nameQuery = {category: req.params.categoryname};
Recipe.find(nameQuery, (err, recipes) => {
if (err) throw err;
res.json(recipes);
});
});
// Now it's working, good stuff.
router.post('/addrecipe', (req, res, next) => {
Recipe.create({
name: req.body.name,
description: req.body.description,
steps: req.body.steps,
ingredients: req.body.ingredients,
category: req.body.category,
}, (err, recipe) => {
if (err) throw err;
// Recipe.save();
res.json(recipe);
});
});
// See if this works
router.put('editrecipe/:recipename/:editedField', (req, res, next) => {
Recipe.findOneAndUpdate({name: req.params.recipename}, {$set: req.body}, {new: true}, (err, recipe) => {
if (err) throw err;
res.json(recipe)
});
});
// It's working, thank god
router.delete('/deleterecipe/:recipename', (req, res, next) => {
let nameQuery = {name: req.params.recipename};
Recipe.findOneAndRemove(nameQuery, (err, recipe) => {
if (err) throw err;
res.send('Dish was succesfully deleted!')
});
});
module.exports = router;
And here is my app.js file
let express = require('express');
let mongoose = require('mongoose');
let path = require('path');
let bodyParser = require('body-parser');
let recipeRouter = require('./routes/recipeRouter');
let userRouter = require('./routes/userRouter');
let bcrypt = require('bcrypt');
let passport = require('passport');
let LocalStrategy = require('passport-local').Strategy;
let config = require('./config');
mongoose.connect(config.mongoUrl);
let db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function () {
// we're connected!
console.log("Connected correctly to server");
});
const app = express();
const port = 3000;
app.listen(port);
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());
app.set('views', path.join(__dirname, 'views'));
app.use('/users', userRouter);
app.use('/recipes',recipeRouter);
app.get('/', function(req, res){
res.send('Hey, this is your database!')
});
module.exports = app;
And here is my Recipe file
const express = require('express');
const mongoose = require('mongoose');
const User = require('../models/user');
let Schema = mongoose.Schema;
let commentSchema = Schema({
rating: {
type: Number,
required: true,
min: 1,
max: 5,
},
comment: {
type: String,
required: true
},
postedBy: {
type: Schema.Types.ObjectId,
ref: 'User'
}
});
let Comment = mongoose.model('Comment', commentSchema);
let recipeSchema = Schema({
name: {
type: String,
required: true
},
description: {
type: String,
},
steps: {
type: String,
required: true,
},
ingredients: {
type: Array,
required: true
},
comments: [commentSchema],
category: {
type: String,
required: true,
},
postedBy: {
type: Schema.Types.ObjectId,
ref: 'User'
}
});
/// So I learnt that by defining the string as "Recipe" in the model function, I will have to lower case it
/// and pluralize it when I use it with res.json and other such things (i.e. "Recipe" => recipes).
let Recipe = mongoose.model('Recipe', recipeSchema);
module.exports = Recipe;
/// refactor this so that these are in the router, not in the models file
/*
module.exports.getRecipeByName = (name, callback) => {
let nameQuery = {name: name};
Recipe.findOne(nameQuery, callback);
};
module.exports.getRecipesByCategory = (category, callback) => {
Recipe.find({'category': category});
};
*/

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