Node + Express: How to retrieve data from MongoDB via Azure - node.js

Question

I am a frontend developer. A colleague has kindly built me a MongoDB/Cosmos database in Azure and allowed me to retrieve a single record into my frontend. He has since gone on holiday with no cover.
(I am confused what type of database it is, since it says Azure Cosmos DB in Azure portal, but all the code in my server.js file refers to a MongoDB.) Server.js:
const express = require('express');
const app = express();
const url = 'mongodb://blah.azure.com';
app.use(express.static('static'));
const mongoClient = require('mongodb').MongoClient
let db;
app.listen(process.env.PORT || 3000, async () => {
console.log('App listening on port 3000!')
const connect = await mongoClient.connect(url)
db = connect.db('ideas');
});
app.get('/api/ideas/:name', async (req, res) => {
return res.json(await db.collection('container1').findOne({key: req.params.name}));
});
I want to retrieve all documents in this database. They each have an ID. But my colleague seems to have defined an API by name. From the MongoDB docs I can use the command find({}) instead of findOne({key: req.params.name}) to return all records, but this does not work (i.e. I get no output to the console). I presume this is because of the '/api/ideas/:name'.
I have also tried:
db.open(function(err, db){
var collection = db.collection("container1");
collection.find().toArray(function(err2, docs){
console.log('retrieved:');
console.log(docs);
})
})
but i get an error that tells me I can't retrieve the property "open" of undefined.
Can anyone help me either: (1) work out how to change the API in Azure, or (2) rewrite this code to retrieve all records? I will also need to edit and insert records. Thanks

Answer 1

If you want to retrive data from Mongo DB in nodejs espresso application, I suggest you use the package mongoose.
For example
Create mongo.js file to add connection details
const mongoose = require('mongoose');
mongoose.Promise = global.Promise;
const accountName= 'testmongo05',
const databaseName= 'test',
const key= encodeURIComponent(''),
const port: 10255
const mongoUri = `mongodb://${env.accountName}:${key}#${accountName}.documents.azure.com:${port}/${databaseName}?ssl=true`;
function connect() {
mongoose.set('debug', true);
return mongoose.connect(mongoUri, {
useFindAndModify : false,
useCreateIndex: true,
useNewUrlParser: true,
useUnifiedTopology: true
});
}
module.exports = {
connect,
mongoose
};
Define models
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const userSchema = new Schema(
{
userId: {
type: String,
required: true,
unique: true
},
name: String,
saying: String
},
{
collection: 'Users'
}
);
const User = mongoose.model('User', userSchema);
module.exports = User;
CURD operations
const express = require('express');
const bodyParser = require('body-parser');
const User = require('./module/user');
const app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
require('./mongo').connect().catch(error => console.log(error));
//list users
app.get('api/users', async (req, res) => {
const docquery = User.find({});
await docquery
.exec()
.then(users => {
res.status(200).json(users);
})
.catch(error => {
res.status(500).send(error);
});
});
// get user by userId
app.get('/api/user/:uid', async (req, res) => {
const docquery =User.findOne({userId:req.params.uid })
await docquery
.exec()
.then(user => {
if (!checkFound(res, user)) return;
res.status(200).json(user);
})
.catch(error => {
res.status(500).send(error);
});
});
// create
app.post('/api/user', async (req, res) => {
const originalUser= { userId: req.body.userId, name: req.body.name, saying: req.body.saying };
const user = new User(originalUser);
await user.save(error => {
if (checkServerError(res, error)) return;
res.status(201).json('User created successfully!');
console.log('User created successfully!');
});
});
//update user by userId
app.put('/api/user/:uid', async (req, res) => {
const docquery =User.findOneAndUpdate({userId: req.params.uid}, req.body)
await docquery.exec()
.then((user) =>{
if (!checkFound(res, user)) return;
res.status(200).json("User update successfully");
console.log('User update successfully!');
})
.catch(error =>{
res.status(500).send(error);
})
});
//delete user by userId
app.delete('/api/user/:uid', async (req, res) => {
const docquery = User.findOneAndRemove({userId: req.params.uid })
await docquery.exec()
.then(user =>{
if (!checkFound(res, user)) return;
res.status(200).json("user deleted successfully!");
console.log('user deleted successfully!');
})
.catch(error =>{
res.status(500).send(error);
})
});
function checkServerError(res, error) {
if (error) {
res.status(500).send(error);
return error;
}
}
function checkFound(res, user) {
if (!user) {
res.status(404).send('user not found.');
return;
}
return user;
}
Test
a. Create user
b. get user
c. List Users
d. Update User
e delete user