Indexed list with attributes

[Michal Cicatka]

I have a list of items which includes null and I would like to map it to my DB using the  NHibernate.Mapping.Attributes. This is my source code but it does not work. What am I doing wrong? 

A little background: I have a Project class that contains List of "CPTItem". The "ItemIndex" is a column in the database which should be used to retrieve ordered list with null gaps. My BussinessBindingList is a class that implements IBindingList interface.

[List(0, Table = "CPT_Items", Cascade = "all-delete-orphan", CollectionTypeType = typeof(BusinessBindingList<CPTItem>))]

[Key(1, Column = "ProjectID")]

[ListIndex(2, Column = "ItemIndex")]

[OneToMany(3, ClassType = typeof(CPTItem))]
public virtual IBindingList< CPTItem> ColonyPicks { get; protected set; }