laravel eloquent subquery select join concatenate code example

Example 1: join in laravel eloquent

$customer = DB::table('customers')
                ->join('shops', 'customers.shop_id', '=', 'shops.shop_id')
                ->where('customer_contact', $contact_no)
                ->get();

Example 2: laravel + join 2 eloquent queries

$select->joinSub(
                    $selectSubQry,
                    'ag',
                    'ag.id',
                    '=',
                    'agp.userId'
                );