Laravel relationship does not load related data when using findOrFail method.

When working with Laravel relationships, you might encounter a situation where you expect the related data to be loaded when using the findOrFail method, but it doesn't happen. In this answer, we will discuss the reasons behind this behavior and provide possible solutions.

First, let's clarify what the findOrFail method does. This method is a convenience method provided by Laravel's Eloquent ORM to find a record by its primary key. If the record is not found, an exception will be thrown. The method is defined in the Model base class, so it is available for all Eloquent models.

By default, when you call the findOrFail method, only the primary record is loaded. The related records are not loaded automatically. This behavior is intentional, as it helps to prevent unnecessary database queries and improve application performance.

However, if you need to load the related records along with the primary record, you have several options:

Use eager loading: Eager loading is a technique to load related records in a single query. You can use the with method to eagerly load the relationships. Here's an example:

$record = Model::with('relation')->findOrFail($id);

In this example, Model is the name of the Eloquent model, and relation is the name of the relationship.

Use lazy loading: Lazy loading is a technique to load related records on demand. You can use the accessor or relationship method to load the related records when you need them. Here's an example:

class Model extends Model
{
    public function relation()
    {
        return $this->hasOne(RelationModel::class);
    }

    public function getRelationAttribute()
    {
        return $this->relation->load('related');
    }
}

// Use the relation attribute to load the related records
$record = Model::findOrFail($id);
$related = $record->relation;

In this example, Model and RelationModel are the names of the Eloquent models, and relation is the name of the relationship. The getRelationAttribute method is an accessor that loads the related records when the relation property is accessed.

Use the withCount method: If you only need to count the related records, you can use the withCount method to eagerly load the relationship with the count. Here's an example:

$record = Model::withCount('relation')->findOrFail($id);

In this example, Model is the name of the Eloquent model, and relation is the name of the relationship.

By using one of these techniques, you can load the related records when using the findOrFail method in Laravel.