MySQL 两条语句的合并查询问题

Question

// 查询一
$sql = "SELECT sum(`real_price`) total_real_price FROM `order` WHERE `wid` = 200 AND `type` = 2 AND `is_pay` = '1' AND `deleted_at` IS NULL";
$result_real = $this->model->dbconfig('aa')->query($sql)->find();

// 查询二
$sql = "SELECT sum(`balance_price`) total_balance_price FROM `order` WHERE `wid` = 200 AND `type` = 3 AND `is_pay` = '1' AND `deleted_at` IS NULL";
$result_balance_price = $this->model->dbconfig('aa')->query($sql)->find();

如何将这样的语句合并成一条语句查询呢？