Simplifying Relationship Queries with Laravel's whereAttachedTo Method
Navigating relationships in Laravel's Eloquent ORM just got more elegant with the introduction of the whereAttachedTo() method—a powerful shorthand that simplifies one of the most common relationship queries developers write.
The Challenge with Many-to-Many Filters
If you've worked with Laravel's Eloquent ORM, you're likely familiar with the pattern of filtering models based on their relationships. This is especially common when dealing with many-to-many relationships.
For example, imagine you want to find all blog posts that are tagged with specific tags. Traditionally, you'd write something like this:
$tags = Tag::where('created_at', '>', now()->subMonth())->get();
$taggedPosts = Post::whereHas('tags', function ($query) use ($tags) {
$query->whereKey($tags);
})->get();
While this approach works, it introduces verbosity and complexity to your code. You need to define a closure, use the $tags variable, and understand how to properly construct the inner query.
Enter whereAttachedTo()
Laravel now offers a more elegant solution with the whereAttachedTo() method:
$tags = Tag::where('created_at', '>', now()->subMonth())->get();
$taggedPosts = Post::whereAttachedTo($tags)->get();
This new method provides a clean, expressive way to filter models based on their BelongsToMany relationships. The code is shorter, more readable, and better communicates the intention: "Give me posts attached to these tags."
Specifying the Relationship
By default, whereAttachedTo() will try to infer the relationship name from the model type you pass. However, you can explicitly specify the relationship name when needed:
$taggedPosts = Post::whereAttachedTo($tags, 'tags')->get();
This is particularly useful when you have multiple relationships with the same model type or when the inferred name might not match your actual relationship name.
Real-World Example
Let's look at a practical example in a controller method for a blog application:
class PostController extends Controller
{
public function indexByTags(Request $request)
{
// Get selected tags from request
$tagIds = $request->input('tags', []);
$tags = Tag::findMany($tagIds);
// Query posts with those tags
$posts = Post::whereAttachedTo($tags)
->with(['author', 'comments'])
->latest()
->paginate(15);
return view('posts.index', compact('posts', 'tags'));
}
}
This controller method handles a request to filter blog posts by selected tags. The whereAttachedTo() method streamlines the query, making it more readable and maintainable.
Stay up to date with more Laravel tips and tricks by following me: