NHibernate - Is it possible to map columns into collection composite objects - nhibernate

Question

Using NHibernate is it possible to map columns in a table to a collection of objects.
For example if I have a very badly designed database table with columns as such:
ClientID
ClientName
First_AmountPaid
Second_AmountPaid
Third_AmountPaid
Fourth_AmountPaid
Is it possible to map this to the following class structure where First_AmountPaid through to Fourth_AmountPaid have their own class implementation?
public class Client
{
public int ClientId { get; set; }
public string ClientName { get; set; }
public IList<AmountPaid> Amounts { get; set; }
}
public class AmountPaid
{
public decimal Amount { get; set; }
}
public class FirstAmountPaid : AmountPaid{ }
public class SecondAmountPaid : AmountPaid{ }
public class ThirdAmountPaid : AmountPaid{ }
public class FourthAmountPaid : AmountPaid{ }
Therefore giving a more meaningful code structure.
Thank you

Answer 1

i'm not sure why there are subclasses when the listposition already defines the order of the amounts
Map(x => x.Amounts)
.Columns.Add("First_AmountPaid", "Second_AmountPaid", "Third_AmountPaid", "Fourth_AmountPaid")
.CustomType<AmountPaidType>();
class AmountPaid : IUserType
{
public object Assemble(object cached, object owner)
{
return cached;
}
public object DeepCopy(object value)
{
return ((IList<AmountPaid>)x).Select(a => a.Clone()).ToList();
}
public object Disassemble(object value)
{
return value;
}
bool IUserType.Equals(object x, object y)
{
// assuming AmountPaid implements Equals
return ((IList<AmountPaid>)x).SequenceEquals((IList<AmountPaid>)y);
}
public int GetHashCode(object x)
{
return x.GetHashCode();
}
public bool IsMutable
{
get { return true; }
}
public void NullSafeSet(cmd, value, index)
{
var list = (IList<AmountPaid>)value;
NHibernateUtil.Double.NullSafeSet(cmd, list[0].Amount, index);
NHibernateUtil.Double.NullSafeSet(cmd, list[1].Amount, index + 1);
NHibernateUtil.Double.NullSafeSet(cmd, list[2].Amount, index + 2);
NHibernateUtil.Double.NullSafeSet(cmd, list[3].Amount, index + 3);
}
public object NullSafeGet(rs, names, owner)
{
var list = new List<AmountPaid>();
foreach (var name in names)
{
list.Add(new AmountPaid((double)NHibernateUtil.Double.Get(rs, name)));
}
return list;
}
public object Replace(object original, object target, object owner)
{
return original;
}
public Type ReturnedType
{
get { return typeof(IList<AmountPaid>); }
}
public SqlType[] SqlTypes
{
get { return new[] { SqlTypeFactory.Double, SqlTypeFactory.Double, SqlTypeFactory.Double, SqlTypeFactory.Double }; }
}
}