Answers for "eloquent select as"

eloquent with select

Post::query()
    ->with(array('user' => function($query) {
        $query->select('id','username');
    }))
    ->get();

join in laravel eloquent

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