Joining pivot table to access data - laravel

Question

I am trying to access data from a database query which I think will need a join. I have users that can be apart of many groups. I am using a belongsToMany
relationship. My Models are like so
class User extends Model
{
protected $table = 'users';
protected $guarded = [];
public function group()
{
return $this->belongsToMany('App\Group', 'users_user_groups')->withPivot('user_id', 'group_id');
}
}
class Group extends Model
{
protected $table = 'user_groups';
protected $guarded = [];
use SoftDeletes;
public function user()
{
return $this->belongsToMany('App\User', 'users_user_groups')->withPivot('user_id', 'group_id');
}
}
When I run everything I need too, I might get data like the following.
users
+----+---------------+
| id | name |
+----+---------------+
| 1 | John Doe |
+----+---------------+
user_groups
+----+---------------+-----------------+
| id | name | description |
+----+---------------+-----------------+
| 1 | Group AA | Something |
+----+---------------+-----------------+
| 2 | Group BB | Something |
+----+---------------+-----------------+
users_user_groups
+----+---------------+-----------------+
| id | user_id | group_id |
+----+---------------+-----------------+
| 1 | 1 | 1 |
+----+---------------+-----------------+
| 2 | 1 | 2 |
+----+---------------+-----------------+
So I know user with the id 1 belongs to the user_groups with ids of 1 and 2. What I am trying to do is grab all the users within my database who
belong to a user_group with the name admin. So I am trying something like this
DB::table('users')->select('userName')
->join('user_groups', 'users_user_groups')
->where('name', '=', 'admin')->get();
This I know is all wrong, how can I get all users within a group when using belongsToMany and a pivot table?
Thanks

Answer 1

Eloquent uses relations, not the query builder.
You can achieve what you're aiming for by doing something like this:
$group = Group::where('name', 'admin')->first();
$users = $group->users; // Where users is the name of your relationship (At the moment you have user)
Under the hood that will do two SQL statements and map them together in eloquent objects, rather than a join. The statements will look something like this:
select * from user_groups where name = ? and deleted_at is not null limit 1
select * from users where id in (?, ?)
When you have an instance Group you execute the relationship by calling it as if it was a property. So after that $users will contain a collection of User instances, so you can just loop through them:
foreach ($users as $user) {
// Do something with $user
}