laravel whereExists

//只能查出闭包外的表有的字段数据
$users = DB::table('users')
           ->whereExists(function ($query) {
           		//查询出与这表相对应的字段相等的数据
               $query->select(DB::raw(1))
                     ->from('orders')
                     ->whereRaw('orders.user_id = users.id');
           })
           ->get();
           
SQL:select * from users
where exists (
    select 1 from orders where orders.user_id = users.id
)