Eloquent: Collections
Introduction
All multi-result sets returned by Eloquent are instances of the Illuminate\Database\Eloquent\Collection
object, including results retrieved via the get
method or accessed via a relationship. The Eloquent collection object extends the Laravel base collection, so it naturally inherits dozens of methods used to fluently work with the underlying array of Eloquent models.
All collections also serve as iterators, allowing you to loop over them as if they were simple PHP arrays:
$users = App\User::where('active', 1)->get();
foreach ($users as $user) {
echo $user->name;
}
However, collections are much more powerful than arrays and expose a variety of map / reduce operations that may be chained using an intuitive interface. For example, let's remove all inactive models and gather the first name for each remaining user:
$users = App\User::all();
$names = $users->reject(function ($user) {
return $user->active === false;
})
->map(function ($user) {
return $user->name;
});
While most Eloquent collection methods return a new instance of an Eloquent collection, the pluck
, keys
, zip
, collapse
, flatten
and flip
methods return a base collection instance. Likewise, if a map
operation returns a collection that does not contain any Eloquent models, it will be automatically cast to a base collection.
Available Methods
All Eloquent collections extend the base Laravel collection object; therefore, they inherit all of the powerful methods provided by the base collection class.
In addition, the Illuminate\Database\Eloquent\Collection
class provides a superset of methods to aid with managing your model collections. Most methods return Illuminate\Database\Eloquent\Collection
instances; however, some methods return a base Illuminate\Support\Collection
instance.
contains diff except find fresh intersect load loadMissing modelKeys makeVisible makeHidden only toQuery unique
contains($key, $operator = null, $value = null)
The contains
method may be used to determine if a given model instance is contained by the collection. This method accepts a primary key or a model instance:
$users->contains(1);
$users->contains(User::find(1));
diff($items)
The diff
method returns all of the models that are not present in the given collection:
use App\User;
$users = $users->diff(User::whereIn('id', [1, 2, 3])->get());
except($keys)
The except
method returns all of the models that do not have the given primary keys:
$users = $users->except([1, 2, 3]);
find($key)
The find
method finds a model that has a given primary key. If $key
is a model instance, find
will attempt to return a model matching the primary key. If $key
is an array of keys, find
will return all models which match the $keys
using whereIn()
:
$users = User::all();
$user = $users->find(1);
fresh($with = [])
The fresh
method retrieves a fresh instance of each model in the collection from the database. In addition, any specified relationships will be eager loaded:
$users = $users->fresh();
$users = $users->fresh('comments');
intersect($items)
The intersect
method returns all of the models that are also present in the given collection:
use App\User;
$users = $users->intersect(User::whereIn('id', [1, 2, 3])->get());
load($relations)
The load
method eager loads the given relationships for all models in the collection:
$users->load('comments', 'posts');
$users->load('comments.author');
loadMissing($relations)
The loadMissing
method eager loads the given relationships for all models in the collection if the relationships are not already loaded:
$users->loadMissing('comments', 'posts');
$users->loadMissing('comments.author');
modelKeys()
The modelKeys
method returns the primary keys for all models in the collection:
$users->modelKeys();
// [1, 2, 3, 4, 5]
makeVisible($attributes)
The makeVisible
method makes attributes visible that are typically "hidden" on each model in the collection:
$users = $users->makeVisible(['address', 'phone_number']);
makeHidden($attributes)
The makeHidden
method hides attributes that are typically "visible" on each model in the collection:
$users = $users->makeHidden(['address', 'phone_number']);
only($keys)
The only
method returns all of the models that have the given primary keys:
$users = $users->only([1, 2, 3]);
toQuery()
The toQuery
method returns an Eloquent query builder instance containing a whereIn
constraint on the collection model's primary keys:
$users = App\User::where('status', 'VIP')->get();
$users->toQuery()->update([
'status' => 'Administrator',
]);
unique($key = null, $strict = false)
The unique
method returns all of the unique models in the collection. Any models of the same type with the same primary key as another model in the collection are removed.
$users = $users->unique();
Custom Collections
If you need to use a custom Collection
object with your own extension methods, you may override the newCollection
method on your model:
<?php
namespace App;
use App\CustomCollection;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
/**
* Create a new Eloquent Collection instance.
*
* @param array $models
* @return \Illuminate\Database\Eloquent\Collection
*/
public function newCollection(array $models = [])
{
return new CustomCollection($models);
}
}
Once you have defined a newCollection
method, you will receive an instance of your custom collection anytime Eloquent returns a Collection
instance of that model. If you would like to use a custom collection for every model in your application, you should override the newCollection
method on a base model class that is extended by all of your models.