Getting specific columns with eager loading laravel 4

Question

I am new to laravel and making a basic application to get a grip on relationships.I have implemented one to one relationship and want to get specific columns from both the base table and the related table.I have two tables namely users and identity_cards.Relationship is defined as follows

class User extends Eloquent implements UserInterface, RemindableInterface {

    use UserTrait, RemindableTrait;

    /**
     * The database table used by the model.
     *
     * @var string
     */
     protected $table = 'users';

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    //protected $hidden = array('password', 'remember_token');

    protected $fillable = array('first_name','last_name','email','created_at','updated_at');

    public function identity_cards() 
    {
        return $this->hasOne('IdentityCard');
    }
}


class IdentityCard extends Eloquent {

    protected $table    = 'identity_cards';
    protected $fillable = array('issuance_date','expiry_date','issuance_location','user_id');
    public $timestamps  = false;

    public function user()
    {
       return $this->belongsTo('User');
    }
}

Everything works fine when i try to retrieve all the columns

$users = User::with('identity_cards')->get()->toArray();

But when i try to get specific columns from either or both the tables,i got an empty array against the record for identity card table

 $users = User::with(array('identity_cards'),function($query) {
                $query->select('issuance_location'); //getting specific column from identity card table
              }
          )->get(array("first_name"))->toArray();

Result against the above statement is as follows:-

Array
(
    [0] => Array
    (
        [first_name] => User1
        [identity_cards] => 
    )

    [1] => Array
    (
        [first_name] => User2
        [identity_cards] => 
    )

    [2] => Array
    (
        [first_name] => User3
        [identity_cards] => 
    )

 )

This can be achieved using query builder but i want the solution with eloquent.Why am i getting an empty array for my related table even if i have the data in it.How specific columns can be fetched using eager loading??

Jarek Tkaczyk · Accepted Answer · 2014-09-18 08:21:49Z

7

1 You need to always select primary key of the parent and foreign key of the child of a relation, otherwise Eloquent won't be able to match related models.

2 Closure passed to the eager loading is a value of the array, not 2nd parameter of with function:

User::with(array('identity_cards' => function($query) {
            $query->select('issuance_location', 'user_id');
      }))->get(array('first_name', 'id'))->toArray();

3 I would rename that relation to identity_card, for it's hasOne - it will be easier to work with.

answered Sep 18, 2014 at 8:21

Jarek Tkaczyk

81.4k27 gold badges167 silver badges162 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jarek Tkaczyk Over a year ago

Mark it as correct answer then, in case anyone else has the same problem.

Vit Kos · Accepted Answer · 2014-09-18 08:21:39Z

0

One of the solution would be just making a new relation similar to that you have made, but tweaking it a bit, for conviniece :

public function identity_cards_limited() 
    {
        return $this->hasOne('IdentityCard')->select('desired_column');
    }

answered Sep 18, 2014 at 8:21

Vit Kos

5,8155 gold badges47 silver badges59 bronze badges

1 Comment

developer34 Over a year ago

I saw this option but this will limit my scope when i want to retrieve one set of columns for one query and other set for another query.For example,in one scenerio i need id and expiry date of card and in other scenerio, i need issuance date only.For table with greater number of columns this would be an overhead to specify many column names.But yes this is a good option too :).Thanks for your help :)

Collectives™ on Stack Overflow

Getting specific columns with eager loading laravel 4

2 Answers 2

1 Comment

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related