Question

Look the mapping below.

When I do :
session.Get<Customer>(theId); The result return is the right customer but the Address list is empty. In the database, I see the customer record and the address. The address record in the field Customer_id (generated by NHibernate) is not null and has the right value (id of the customer).

Class and Mapping

public class Customer
{
    public virtual int Id { get; set; }
    public virtual string LastName { get; set; }
    public virtual Iesi.Collections.Generic.ISet<CustomerAddress> Address { get; set; }

    public Customer()
    {
        Address = new Iesi.Collections.Generic.HashedSet<CustomerAddress>(); 
    }
}

public class CustomerAddress
{
    public virtual int Id { get; set; }
    public virtual string Street { get; set; }
    public virtual Customer Customer { get; set; }
}

public class CustomerMap : ClassMap<Customer>
{
    public CustomerMap()
    {
        Id(x => x.Id).GeneratedBy.Native();
        Map(x => x.LastName)
            .Length(50)
            .Not.Nullable();    
        HasMany(x => x.Address)
            .AsSet()
            .Inverse()
            .Cascade.AllDeleteOrphan();
    }
}

public class CustomerAddressMap : ClassMap<CustomerAddress>
{
    public CustomerAddressMap()
    {
        Id(x => x.Id).GeneratedBy.Native();
        Map(x => x.Street).Length(50);
        References(x => x.Customer);
    }
}

Answer 1

Lazy loading is enabled by default, which means you won’t retrieve the addresses until you touch the Address property. You can disable lazy loading in your mapping with:

HasMany(x => x.Address)
        .AsSet()
        .Inverse()
        .Cascade.AllDeleteOrphan()
        .Not.LazyLoad();