Fluent NHibernate mapping one-to-many - fluent-nhibernate

Question

Hello i got problem with my mappings using fluent nhibernate:
public ProductMap()
{
Id(x => x.ProductID);
Map(x => x.ProductName);
Map(x => x.QuantityPerUnit);
Map(x => x.ReorderLevel);
Map(x => x.SupplierID);
Map(x => x.UnitPrice);
Map(x => x.UnitsInStock);
Map(x => x.UnitsOnOrder);
Map(x => x.CategoryID);
Map(x => x.Discontinued);
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
Table("dbo.Products");
}
public SupplierMap()
{
Id(x => x.SupplierID);
Map(x => x.Address);
Map(x => x.City);
Map(x => x.CompanyName);
Map(x => x.ContactName);
Map(x => x.ContactTitle);
Map(x => x.Country);
Map(x => x.Fax);
Map(x => x.HomePage);
Map(x => x.Phone);
Map(x => x.PostalCode);
Map(x => x.Region);
HasMany(x => x.Products)
.KeyColumn("SupplierID")
.Inverse()
.Cascade.All();
Table("dbo.Suppliers");
}
public CategoryMap()
{
Id(x => x.CategoryID);
Map(x => x.CategoryName);
Map(x => x.Description);
Map(x => x.Picture);
HasMany(x => x.Products)
.KeyColumn("CategoryID")
.Inverse()
.Cascade.All();
Table("dbo.Categories");
}
when i try to do:
var sessionFactory = SessionFactory.CreateSessionFactory();
using (var session = sessionFactory.OpenSession())
{
Product fresh = new Product()
{
ProductName = "AddFromNhibernate",
SupplierID = 3,
CategoryID = 5,
QuantityPerUnit = "1kg pcg",
UnitPrice = (decimal) 35,
UnitsInStock = (short?) 15,
UnitsOnOrder = 0,
ReorderLevel = null,
Discontinued = true
};
using (session.BeginTransaction())
{
session.Save(fresh);
session.Transaction.Commit();
}
}
I got System.IndexOutOfRangeException.
Whats wrong with my mappings?The work ok when i try to get some data, but adding fails. I trierd to specyfie Propertyreference for Reference in ProductMap but it didn't help.

Answer 1

I noticed you mapped some columns twice.
Take ProductMap as an example:
public ProductMap()
{
(...)
Map(x => x.SupplierID);
(...)
Map(x => x.CategoryID);
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
(...)
}
In this case, if you want to preserve the original ID and the reference (since they map to the same column in the database table), you should bypass the Insert/Update in one of them.
What I mean is:
public ProductMap()
{
(...)
Map(x => x.SupplierID).Not.Insert().Not.Update();
(...)
Map(x => x.CategoryID).Not.Insert().Not.Update();
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
(...)
}
If you dot not do so, you might get the Exception you described when NHibernate starts to set the insert/update parameters.