我有一个对象，有2个类列表。
public class Order
{
int order_id;
double amount;
List<order_item> order_items;
List<order_shipment> order_shipments;
}
下面是映射对象的方法:
SELECT * FROM Orders o
INNER JOIN Order_Items i ON i.order_id = o.order_id
INNER JOIN Order_Shipments s ON s.order_id = o.order_id
将上述查询映射到嵌套类的方法是什么？
试一试:
var orders =
conn.Query<Order, order_item, order_shipment>(@"
SELECT o.*,i.*,s.* FROM Orders o
INNER JOIN Order_Items i ON i.order_id = o.order_id
INNER JOIN Order_Shipments s ON s.order_id = o.order_id
", (order, orderItem, orderShipment) => {
order.order_items = order.order_items ?? new List<order_item>();
order.order_items.Add(orderItem);
order.order_shipments = order.order_shipments ?? new List<order_shipment>();
order.order_shipments.Add(orderShipment);
return order;
}).AsQueryable();
