dealing with property that does not map directly onto column on the database - petapoco

Question

I have the following tables
Client Table and Product Table
ID
Name
ClientProduct Table
ID
ClientID
ProductID
Product class
private int id;
public int ID
{
get { return id; }
set { id = value; }
}
protected string name;
public Product () { }
public Product (string name)
{
this.name = name;
}
public Product (string name)
{
this.name = name;
}
public string Name
{
get { return name; }
set { name = value; }
}
Client class
private int id;
public int ID
{
get { return id; }
set { id = value; }
}
protected string name;
public Client () { }
public Client (string name)
{
this.name = name;
}
public Client (string name)
{
this.name = name;
}
public string Name
{
get { return name; }
set { name = value; }
}
ClientProduct class
protected Client client;
protected Product product;
public ClientProduct () { }
public ClientProduct (Client client, Product product)
{
this.client= client;
this.product= product;
}
public Client client {
get { return client; }
set { client= value; }
}
public Product product {
get { return product; }
set { product= value; }
}
How can I do the following in petaPOCO?
public static System.Collections.Generic.IList<ClientProduct> LoadForClient(Client client)
{
if (null != client)
return Load("ClientID = " + client.ID);
else
return null;
}
such that I can have list of all products for that client that I will later used in my view as
private void LoadProducts(Client client )
{
Products = ClientProduct.LoadForClient(client)
.Select(x => x.Product.Name)
.OrderBy(x => x).ToArray();
}

Answer 1

The 1:M and M:1 relationships seem like what you're after
http://www.toptensoftware.com/Articles/115/PetaPoco-Mapping-One-to-Many-and-Many-to-One-Relationships
You can define a custom relator callback; Brad's example for two tables (if your products mapped directly to the client) would look something like this:
var posts = db.Fetch<Product, Client, ClientProduct>(
(p,c)=> { p.client_obj = c; return p; },
#"SELECT * FROM Product
LEFT JOIN Client ON Product.clientId = Client.id ORDER BY Product.clientId
");
I realize your dealing with a M:M relationship so you would need to update the above to map across the three objects, but the concept is the same. The key is that your 3rd argument in the call (ClientProduct) represents the joined row, and you can then reference the Client and/or Products directly from the single list.