SELECT all with children - sql

Question

I have the following classes:
public class Order
{
public Order()
{
OrderItems = new List<OrderItem>();
}
public int Id { get; set; }
public string OrderName { get; set; }
public int OrderStatusId { get; set; }
public OrderStatus Status { get; set; }
public List<OrderItem> OrderItems { get; set; }
}
public class OrderItem
{
public int Id { get; set; }
public int OrderId { get; set; }
public string ProductName { get; set; }
}
public class OrderStatus
{
public int Id { get; set; }
public string Description { get; set; }
}
For returning a single order I use this method (any comment on it would also be helpful):
Order GetOrder()
{
using (var con = GetConnection())
{
try
{
con.Open();
string query =
#"SELECT * FROM [Order] JOIN OrderStatus ON [Order].OrderStatusId = OrderStatus.Id WHERE [Order].Id =1;
SELECT * FROM OrderItem Where OrderId = 1";
using (var multi = con.QueryMultiple(query))
{
Order order = multi.Read<Order, OrderStatus, Order>
((ord, ordStat) => { ord.Status = ordStat; return ord; })
.FirstOrDefault();
order.OrderItems = multi.Read<OrderItem>().ToList();
return order;
}
}
catch (Exception ex)
{
return null;
}
}
}
I know I can select all of my orders Id values into a collection on a separate query and run the above method in a foreach loop using the collection values as a parameter but I wonder if dapper has a more elegant solution for returning all of my orders instead of just one.

Answer 1

It sounds like you have a list or array of the ids; dapper supports parameter expansion, allowing use with in, for example:
int[] ids = ...
string query =
#"SELECT * FROM [Order]
JOIN OrderStatus ON [Order].OrderStatusId = OrderStatus.Id
WHERE [Order].Id in #ids;
SELECT * FROM OrderItem Where OrderId in #ids";
using (var multi = con.QueryMultiple(query, new { ids }))
{
var orders = multi.Read<Order, OrderStatus, Order>
((ord, ordStat) => { ord.Status = ordStat; return ord; })
.AsList();
var orderItems = multi.Read<OrderItem>().ToLookup(x => x.OrderId);
foreach(var order in orders) // pick out each order's items
order.OrderItems = orderItems[order.Id].ToList();
}
Any use?