After Eloquent query, you can modify rows by using map()
function in Collections.
$users = User::where('role_id', 1)->get()->map(function (User $user) { $user->some_column = some_function($user); return $user;});
However, this is not adviseable for bigger amount of data, cause you're downloading all the records into RAM and then doing the filtering. A better way is to perform such filtering on the database level, in the query.