Laravel Eloquent Relationship Undefinded Property - laravel

Question

I have a Model House and a Model energy_class.
A house has only one energy class. Energy Classes can be assigned to multiple houses. I therefore defined the relationships like this:
House.php
class House extends Model
{
public function energy_class()
{
return $this->hasOne('App\energy_class', 'id', 'energy_class');
}
}
energy_class.php
class energy_class extends Model
{
public function house()
{
return $this->belongsToMany('App\House');
}
}
When passing the House Data to a view like this:
$house = House::with('energy_class')->find($id);
return view('admin.houses.edit')->with('house', $house);
And referencing it on the view like this:
$house->energy_class()->name
I get this error: Undefined property: Illuminate\Database\Eloquent\Relations\HasOne::$name
When doing it like this: $house->energy_class->name I get trying to get property of non-object

Answer 1

Your first suggestion:
$house->energy_class()->name
Does not work, because at this point you only called the relationship, you didn't yet specify from it what you wanted, e.g.:
$house->energy_class()->first()
Your second try returns empty because $house->energy_class (which does the same as the above code), didn't return any results.
There can be various causes for this:
Your relationship is not properly signed up
Your database is not properly setup (have you set up a foreign key in your migration?)
The house actually does not have an energy class filled out
I suspect in your case it might be the second or the third. Could you paste me your migration script?
Edit: PS. if this error occurs because perhaps not each house actually has a an energy class, you could use the following code to check for this:
$house->energy_class ? $house->energy_class->name : "No energy class available";