表order_items的结构如下: name null? type order_id not null number(12) line_item not null number(3) product_id not null number(6) unit_price number(8,2) quantity number(8) sql语句: SELECT product_id, COUNT(order_id) total, unit_price FROM order_items WHERE unit_price>1000 AND COUNT(order_id)>5 GROUP BY product_id, unit_price; 关于该语句说法正确的是: