Laravel get users by id in user model and store them in an array
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
# Mastering Data Retrieval: Getting Users by ID in Laravel Eloquent
Building interconnected systems, like a simple friends list, is a common task in web development. When you store related data in a single column (like a comma-separated string of IDs), you face a classic challenge: how to efficiently retrieve the full model instances from that raw data.
I see you are trying to implement a "friends" system by storing friend IDs as a comma-separated string within your `User` model. You attempted to use an `explode()` function followed by a loop with `findOrFail()`. While this approach is logically sound, it often hides potential performance pitfalls in a Laravel application.
As a senior developer, my goal is not just to make the code *work*, but to make it work *efficiently* and adhere to Laravel's powerful Object-Relational Mapping (ORM) principles. Let’s break down why your initial approach might be problematic and explore the superior Eloquent solutions.
## The Pitfalls of Manual Looping in Eloquent
Your proposed method involves splitting the string and then querying the database inside a loop:
```php
public function getFriends() {
$friendids = explode(',', $this->friends);
$friends = [];
foreach ($friendids as $id) {
$friends[] = User::findOrFail($id); // Potential performance bottleneck
}
return $friends;
}
```
While this successfully retrieves the data, it forces your application to execute $N$ separate database queries (where $N$ is the number of friends) inside a loop. This pattern is known as the N+1 problem, and while it only involves one loop here, repeatedly hitting the database for simple lookups is inefficient and scales poorly as your friend lists grow.
Furthermore, if you are operating within an Eloquent model context, relying on manual string manipulation for relationships bypasses Laravel’s built-in relationship management, which is designed to handle these connections seamlessly.
## The Best Practice: Leveraging Eloquent Relationships
The most robust and performant way to manage "friends" or many-to-many relationships in Laravel is by using Eloquent's many-to-many capabilities via pivot tables. This delegates the complex joining logic to the database engine, which is significantly faster than manual PHP iteration.
### Step 1: Define the Relationship
Assume you have a pivot table (e.g., `friendships`) linking users. You would define a bidirectional relationship in your models. For instance, if User A is friends with User B, this should be stored in the pivot table, not in User A's column directly.
In your `User` model:
```php
public function friends()
{
// Assuming a many-to-many setup via a pivot table
return $this->belongsToMany(User::class, 'friendships');
}
```
### Step 2: Efficient Retrieval using `whereIn`
If you absolutely must work with IDs stored in a string format (perhaps for legacy reasons), the key is to prepare those IDs into an array and use the highly optimized `whereIn` clause. This tells the database to find all matching records in a single query, drastically reducing overhead.
Let's refine your retrieval method to be efficient:
```php
use App\Models\User;
class User extends Model
{
// ... other model code
public function getFriendsEfficiently()
{
if (empty($this->friends)) {
return [];
}
// 1. Explode the string into an array of IDs
$friendids = explode(',', $this->friends);
// 2. Use whereIn to fetch all related users in a single query
$friends = User::whereIn('id', $friendids)->get();
return $friends;
}
}
```
### Integrating into the View
With this optimized method, your view logic becomes cleaner and faster: