employeeprovider.js

var Db = require('mongodb').Db;
var Connection = require('mongodb').Connection;
var Server = require('mongodb').Server;
var BSON = require('mongodb').BSON;
var ObjectID = require('mongodb').ObjectID;

EmployeeProvider = function(host, port) {
  this.db= new Db('node-mongo-employee', new Server(host, port, {safe: false}, {auto_reconnect: true}, {}));
  this.db.open(function(){});
};


EmployeeProvider.prototype.getCollection= function(callback) {
  this.db.collection('employees', function(error, employee_collection) {
    if( error ) callback(error);
    else callback(null, employee_collection);
  });
};

//find all employees
EmployeeProvider.prototype.findAll = function(callback) {
    this.getCollection(function(error, employee_collection) {
      if( error ) callback(error)
      else {
        employee_collection.find().toArray(function(error, results) {
          if( error ) callback(error)
          else callback(null, results)
        });
      }
    });
};

//save new employee
EmployeeProvider.prototype.save = function(employees, callback) {
    this.getCollection(function(error, employee_collection) {
      if( error ) callback(error)
      else {
        if( typeof(employees.length)=="undefined")
          employees = [employees];

        for( var i =0;i< employees.length;i++ ) {
          employee = employees[i];
          employee.created_at = new Date();
        }

        employee_collection.insert(employees, function() {
          callback(null, employees);
        });
      }
    });
};

EmployeeProvider.prototype.delete = function(employeeId, callback) {
        this.getCollection(function(error, employee_collection) {
                if(error) callback(error);
                else {
                        employee_collection.remove(
                                {_id: employee_collection.db.bson_serializer.ObjectID.createFromHexString(employeeId)},
                                function(error, employee){
                                        if(error) callback(error);
                                        else callback(null, employee)
                                });
                        }
        });
};

exports.EmployeeProvider = EmployeeProvider;