Mongoose CRUD

CRUD Setup

// grab the user model
var User = require('./app/models/user');

// create a new user
var newUser = User({
  name: 'Hemant',
  age: 30
});

Create create a new user

// save the user
newUser.save(function(err) {
  if (err) throw err;

  console.log('User created!');
});

Read

• one specific user

• all users

• similar users

Find All get all the users

// Model.find(conditions, [fields], [options], [callback])

User.find({}, function(err, users) {
  if (err) throw err;

  console.log(users);
});

// No callback... 
// Deferred execution 
var query = User.find();

// With callback... Executes query immediately 
User.find(function (err, results) { 
    // handle the error... Or results here
});  

// With callback and query conditions 
User.find({ memberName: 'Hemant' }, function (err, results) { 
    // handle the error... Or results here 
}); 

// Limit the returned fields... 
User.find({ memberName: 'Hemant' }, 'name, age', function (err, results) { 
    // handle the error... Or results here 
});

// Limit the returned fields with option
// Options examples... skip, limit, sort
User.find({ memberName: 'Hemant' }, 'name, age', { limit: 10 }, function (err, results) { 
    // handle the error... Or results here 
});

Find One

// No callback... No conditions... 
var query = User.findOne(); 
query.exec(function (err, results) { 
    // handle the error... Or results here 
}); 

// With conditions... 
var query = User.findOne({ memberName: ‘Mark’}); 

// With condition, no field filtering, and options... 
var query = User.findOne({ memberName: 'Hemant'}, null, { limit: 10 });

Find By ID

// get a user with ID of 1
User.findById(1, function(err, user) {
  if (err) throw err;

  console.log(user);
});

Querying

// get the date 1 month ago
var monthAgo = new Date();
monthAgo.setMonth(monthAgo.getMonth() - 1);

User.find({ admin: true }).where('created_at').gt(monthAgo).exec(function(err, users) {
  if (err) throw err;

  // show the admins in the past month
  console.log(users);
});


// Model.where(path, [val]) 
Customer.find({ discount: {$gte: 10, $lt: 20}, function(err, results) { 
    if (err) throw err; 
    console.log(results); 
});

Customer.where(‘discount’).gte(10).lt(20).exec(function(err, results) { 
    if (err) throw err; 
    console.log(results); 
});

// Chain where methods together... 
Customer.where(‘discount’).gte(10).lt(20) 
    .where(‘zipCode’, ‘12345’) 
    .exec(function(err, results) { 
        if (err) throw err; 
        console.log(results); 
    });

Querying Operator

$gt greater than 
$gte greater than or equal to 
$in exists in 
$lt less than 
$lte less than or equal to 
$ne not equal to 
$nin does not exist

Update

// Model.update(conditions, update, [options], [callback])

// Example: update multiple documents that match condition 
var condition = { firstName: ‘Bob’ }; 
var update = { firstName: ‘Robert’ }; 
Customer.update(condition, update, { multi: true }, function(err, numberAffected, raw) { 
    // Handle error, returned # affected, and raw response from MongoDB... 
});

Get a User, Then Update

User.findById(1, function(err, user) {
  if (err) throw err;

  user.location = 'uk';

  user.save(function(err) {
    if (err) throw err;

    console.log('User successfully updated!');
  });
});

Find and Update

// find the user hemant
// update him to Varun
User.findOneAndUpdate({ username: 'hemant' }, { username: 'Varun' }, function(err, user) {
  if (err) throw err;

  console.log(user);
});

Find By ID and Update

// find the user with id 4
// update username to Hemant
User.findByIdAndUpdate(4, { username: 'Hemant' }, function(err, user) {
  if (err) throw err;

  console.log(user);
});

Delete

Get a User, Then Remove

User.find({ username: 'hemant' }, function(err, user) {
  if (err) throw err;

  user.remove(function(err) {
    if (err) throw err;

    console.log('User successfully deleted!');
  });
});

Find and Remove

// find the user with id 4
User.findOneAndRemove({ username: 'hemant' }, function(err) {
  if (err) throw err;

  console.log('User deleted!');
});

Find By ID and Remove

// find the user with id 4
User.findByIdAndRemove(4, function(err) {
  if (err) throw err;

  console.log('User deleted!');
});