Efficient data filtering with whereIn() in Laravel

What is whereIn()?

whereIn() is a Laravel Eloquent/Query Builder method that adds a WHERE IN (...) clause to your SQL query. It is used to filter records where a column's value exists within a given array.

Use Case Example

Let’s say you have a users table and you want to get all users whose id is either 1, 2, or 3.

Step-by-Step Tutorial

Step 1: Define Your Data

Define the list of values you want to filter against:

$userIds = [1, 2, 3];

Step 2: Use whereIn() in Eloquent

$users = \App\Models\User::whereIn('id', $userIds)->get();

This will generate the SQL:

SELECT * FROM users WHERE id IN (1, 2, 3);

Step 3: Use whereIn() in Query Builder

$users = DB::table('users')->whereIn('id', $userIds)->get();

It works the same way and is useful when you're not using Eloquent models.

Step 4: Add Additional Conditions (Optional)

You can chain whereIn() With other conditions:

$users = \App\Models\User::whereIn('id', [1, 2, 3])
    ->where('status', 'active')
    ->get();

Step 5: Use whereIn() with Relationships

Example: Get posts by authors whose IDs are in a list.

$authorIds = [5, 6, 7];
$posts = \App\Models\Post::whereIn('user_id', $authorIds)->get();

Tips

• Use whereNotIn() to exclude values:

User::whereNotIn('id', [1, 2, 3])->get();

• You can pass any array—dynamic or hardcoded.

Real-World Example in Controller

public function filterUsers(Request $request)
{
    $ids = $request->input('ids'); // e.g., [2, 5, 9]
    
    $users = User::whereIn('id', $ids)->get();

    return view('users.index', compact('users'));
}

Testing in Tinker

Use Laravel Tinker to test:

php artisan tinker

App\Models\User::whereIn('id', [1, 2])->get();