Don’t Filter by NULL in Collections

You can filter by NULL in Eloquent, but if you're filtering the collection further - filter by empty string, there's no "null" in that field anymore.

// This works$messages = Message::where('read_at is null')->get();// Won’t work - will return 0 messages$messages = Message::all();$unread_messages = $messages->where('read_at is null')->count();// Will work$unread_messages = $messages->where('read_at', '')->count();

Use groupBy on Collections with Custom Callback Function

If you want to group result by some condition which isn’t a direct column in your database, you can do that by providing a closure function.

For example, if you want to group users by day of registration, here’s the code:

$users = User::all()->groupBy(function($item) { return $item->created_at->format('Y-m-d');});

⚠️ Notice: it is done on a Collection class, so performed AFTER the results are fetched from the database.

Multiple Collection Methods in a Row

If you query all results with ->all() or ->get(), you may then perform various Collection operations on the same result, it won’t query database every time.

$users = User::all();echo 'Max ID: ' . $users->max('id');echo 'Average age: ' . $users->avg('age');echo 'Total budget: ' . $users->sum('budget');

Calculate Sum with Pagination

How to calculate the sum of all records when you have only the PAGINATED collection? Do the calculation BEFORE the pagination, but from the same query.

// How to get sum of post_views with pagination?$posts = Post::paginate(10);// This will be only for page 1, not ALL posts$sum = $posts->sum('post_views');// Do this with Query Builder$query = Post::query();// Calculate sum$sum = $query->sum('post_views');// And then do the pagination from the same query$posts = $query->paginate(10);

Serial no in foreach loop with pagination

We can use foreach collection items index as serial no (SL) in pagination.

 ... <th>Serial</th> ... @foreach ($products as $product) <tr> <td>{{ $loop->index + $product->firstItem() }}</td> ... @endforeach

it will solve the issue of next pages(?page=2&...) index count from continue.

Higher order collection methods

Collections have higher order methods, this are methods that can be chained , like groupBy() , map() ... Giving you a fluid syntax. This example calculates theprice per group of products on an offer.

$offer = [ 'name' => 'offer1', 'lines' => [ ['group' => 1, 'price' => 10], ['group' => 1, 'price' => 20], ['group' => 2, 'price' => 30], ['group' => 2, 'price' => 40], ['group' => 3, 'price' => 50], ['group' => 3, 'price' => 60] ]]; $totalPerGroup = collect($offer->lines)->groupBy('group')->map(fn($group) => $group->sum('price')); 

Higher order collection message

Collections also provide support for "higher order messages", which are short-cuts for performing common actions on collections.This example calculates the price per group of products on an offer.

$offer = [ 'name' => 'offer1', 'lines' => [ ['group' => 1, 'price' => 10], ['group' => 1, 'price' => 20], ['group' => 2, 'price' => 30], ['group' => 2, 'price' => 40], ['group' => 3, 'price' => 50], ['group' => 3, 'price' => 60] ]]; $totalPerGroup = collect($offer['lines'])->groupBy->group->map->sum('price');

Get an existing key or insert a value if it doesn't exist and return the value

In Laravel 8.81 getOrPut method to Collections that simplifies the use-case where you want to either get an existing key or insert a value if it doesn't exist and return the value.

$key = 'name';// Still validif ($this->collection->has($key) === false) { $this->collection->put($key, ...);}return $this->collection->get($key);// Using the `getOrPut()` method with closurereturn $this->collection->getOrPut($key, fn() => ...);// Or pass a fixed valuereturn $this->collection->getOrPut($key, $value='teacoders');

Tip given by @Teacoders

Static times method

The static times method creates a new collection by invoking the given closure a specified number of times.

Collectable::times(7, function ($number) { return now()->addDays($number)->format('d-m-Y');});// Output: [01-04-2022, 02-04-2022, ..., 07-04-2022]

Tip given by @Teacoders