NHibernate: Best way to deal with intermediary table using Fluent NHibernate? - nhibernate

Question

How would you map the following in Fluent NHibernate?
See "18.3. Customer/Order/Product"
http://www.hibernate.org/hib_docs/nhibernate/html/example-mappings.html

Answer 1

The following solution uses the same approach as the solution in the example, and the generated XML is as good as the same. I have omitted specifying column names and such things for brevity.
Domain:
public class Customer
{
private ISet<Order> orders = new HashedSet<Order>();
public long Id { get; set; }
public string Name { get; set; }
public ISet<Order> Orders
{
get { return orders; }
private set { orders = value; }
}
}
public class Order
{
public long Id { get; set; }
public DateTime Date { get; set; }
public Customer Customer { get; set; }
public IList<LineItem> LineItems { get; private set; }
}
public class LineItem
{
public int Quantity { get; set; }
public Product Product { get; set; }
}
public class Product
{
public long Id { get; set; }
public string SerialNumber { get; set; }
}
Mapping:
public class CustomerMap : ClassMap<Customer>
{
public CustomerMap()
{
Id(x => x.Id)
.GeneratedBy.Native();
Map(x => x.Name);
HasMany<Order>(x => x.Orders)
.IsInverse()
.AsSet();
}
}
public class OrderMap : ClassMap<Order>
{
public OrderMap()
{
Id(x => x.Id)
.GeneratedBy.Native();
Map(x => x.Date);
References<Customer>(x => x.Customer);
HasMany<LineItem>(x => x.LineItems)
.Component(c =>
{
c.Map(x => x.Quantity);
c.References<Product>(x => x.Product);
}).AsList();
}
}
public class ProductMap : ClassMap<Product>
{
public ProductMap()
{
Id(x => x.Id)
.GeneratedBy.Native();
Map(x => x.SerialNumber);
}
}
To see the generated XML mapping, you can use this code:
Configuration config = new Configuration().Configure();
PersistenceModel model = new PersistenceModel();
model.addMappingsFromAssembly(typeof(CustomerMap).Assembly);
model.Configure(config);
model.WriteMappingsTo("your folder name here");
I hope it helps.
/Erik