如何使用带有Codeigniter的mongoDB选择特定字段？

Question

I am new in mongodb. I want to select the the country and address of particular id

in mysql we will wright it as

"Select address,country from table_name where user_id=value"

how I can implement this in mongodb with codeigniter

here is my user record

array (
  '_id' => '55bb1f3bb117284412000032',
  'name' => 'Sriram',
  'email' => 'sri@gmail.com',
  'password' => '123456',
  'phone' => '354657',
  'tittle' => 'Ms',
  'sname' => 'Kumar',
  'dob' => '07/22/2015',
  'gender' => 'Male',
  'address' => 
  array (
    'address' => 'Pantheon road',
    'street' => 'Egmore',
    'city' => 'Chennai',
  ),
  'country' => 'India',

)

Here is the model file for fetching data

$collection = $this->mongo_db->db->selectCollection('Users');
$profile = $collection->findOne(array('email' => 'athira@gmail.com'));  

I have tried like this

$profile = $collection->findOne(array('email' => 'athira@gmail.com')).country;

but its not working

thank you

Answer 1

Try following and let me know whether it is working or not

$collection->aggregate(
                    array(
                        '$match' => array(
                            '$and' => array(
                                array('email' => 'athira@gmail.com')        
                            )
                        )
                    ),
                    array(
                        '$group' => array(
                            '_id' => '$country'
                        )
                    )
                );

Answer 2

Try this way for codeigniter https://github.com/verkhoumov/codeigniter-mongodb-library

$this->load->library('mongo_db');
$data = $this->mongo_db->select(['address','country'])->where(['user_id'=>$user_id])->get("collection_name");

The required fields can be given in an array to the select([]) function ,it will return the objects with selected fields.