JAVASCRIPT

mongoose in node.js

// getting-started.js
const mongoose = require('mongoose');

main().catch(err => console.log(err));

async function main() {
  await mongoose.connect('mongodb://localhost:27017/test');
}

mongoose node js

// getting-started.js
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test', {useNewUrlParser: true});

Mongoose node js

// getting-started.js
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test', {useNewUrlParser: true});
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function() {
  // we're connected!
});

mongoose in nodem js

const kittySchema = new mongoose.Schema({
  name: String
});

node js + mongoose

const db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function() {
  // we're connected!
});

why we use mongoose

Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node. js. It manages relationships between data, provides schema validation, and is used to translate between objects in code and the representation of those objects in MongoDB.

mongoose node js

var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function() {
  // we're connected!
});

using mongoose with node js

// Create an instance of model SomeModel
var awesome_instance = new SomeModel({ name: 'awesome' });

// Save the new model instance, passing a callback
awesome_instance.save(function (err) {
  if (err) return handleError(err);
  // saved!
});

node js + mongoose

await mongoose.connect('mongodb://localhost/my_database', {  useNewUrlParser: true,  useUnifiedTopology: true});

mongoose in nodem js

const Kitten = mongoose.model('Kitten', kittySchema);

mongoose in nodem js

const silence = new Kitten({ name: 'Silence' });
console.log(silence.name); // 'Silence'

mongoose in nodem js

// NOTE: methods must be added to the schema before compiling it with mongoose.model()
kittySchema.methods.speak = function speak() {
  const greeting = this.name
    ? "Meow name is " + this.name
    : "I don't have a name";
  console.log(greeting);
};

const Kitten = mongoose.model('Kitten', kittySchema);

mongoose in nodem js

const fluffy = new Kitten({ name: 'fluffy' });
fluffy.speak(); // "Meow name is fluffy"

mongoose in nodem js

await fluffy.save();
fluffy.speak();

mongoose in nodem js

const kittens = await Kitten.find();
console.log(kittens);

mongoose in nodem js

await Kitten.find({ name: /^fluff/ });