Detecting & Preventing N+1 Queries in Laravel

The Anatomy of an N+1 Query

When iterating over a collection and calling a relationship method without eager loading, Laravel executes 1 initial query plus N additional queries for each record:

// Triggers 1 query for projects + 50 queries for tasks!
$projects = Project::all();
foreach ($projects as $project) {
    echo $project->tasks->count();
}

Solution: Eager Loading with with()

Eager loading reduces 51 queries to just 2:

$projects = Project::with('tasks')->get();

Or when only counting related records without loading model instances:

$projects = Project::withCount('tasks')->get();

Enforcing Strict Mode in Local Development

Prevent N+1 regressions permanently by putting your models into strict mode in AppServiceProvider:

public function boot(): void
{
    Model::preventLazyLoading(! app()->isProduction());
}