Does a one-to-one relationship in Laravel always need first()?

Question

I have a one-to-one relationship between User and UserSettings models,

But (after $user = auth()->user()) when I try $user->settings()->something it throws an Undefined property error.

It's gone when I use $user->settings()->first()->something...

My question is, is this how it's supposed to work? or am I doing something wrong?

Answer 1

You cannot directly run $user->settings()->something.

Because when you call $user->settings(), it just return Illuminate\Database\Eloquent\Relations\HasOne object.

So it is not the model's object, you need to take the model's object and call its attribute like this.

$user->settings()->first()->something;

---

Dynamic Properties

Since you have one-to-one relationship between User and UserSettings.

If you have a one-to-one relationship in your User model:

public function settings()
{
   return $this->hasOne('App\Models\UserSettings', 'user_id', 'id');
}

According to Laravel doc

Once the relationship is defined, we may retrieve the related record using Eloquent's dynamic properties. Dynamic properties allow you to access relationship methods as if they were properties defined on the model:

Eloquent will automatically load the relationship for you, and is even smart enough to know whether to call the get (for one-to-many relationships) or first (for one-to-one relationships) method. It will then be accessible via a dynamic property by the same name as the relation.

So you can use eloquent's dynamic properties like this:

$user->settings->something; // settings is the dynamic property of $user.

Answer 2

This code will give you a result of collection.

$user->settings;

So calling 'something' is not available or it will return you of null, unless you get the specific index of it.

$user->settings()->something

while this one works because you used first() to get the first data of collection and accessed the properties of it .

$user->settings()->first()->something

The first method returns the first element in the collection that passes a given truth test see docs here laravel docs