Trying to run query for entities when I have Inheritance with fluent Nhibernate - nhibernate

Question

I attempted to extract some common properties to a base class and map with Fluent Nhibernate. In addition, I also attempted to add a second level of inheritance.
//Base entity class
public class EntityBase : IEntityBase
{
public EntityBase()
{
CreatedDate = DateTime.Now;
}
public virtual DateTime? CreatedDate { get; set; }
public virtual int Id { get; set; }
public virtual int Version { get; set; }
}
//Base Entity Mapping
public class EntityBaseMap: ClassMap<EntityBase>
{
public EntityBaseMap()
{
UseUnionSubclassForInheritanceMapping();
Id(x => x.Id);
Version(x => x.Id);
Map(x => x.CreatedDate);
}
}
//first sub class of EntityBase
public class Actuate : EntityBase, IActuate
{
public virtual DateTime? ActivatedOn { get; set; }
}
//Actuate Mapping class
public class ActuateMap : SubclassMap<Actuate>
{
public ActuateMap()
{
Map(x => x.ActivatedOn);
}
}
//Sub class entity
public class Item : Actuate
{
public virtual string Name { get; set; }
public virtual string Description { get; set; }
public virtual decimal UnitPrice { get; set; }
public virtual ItemStatus Status { get; set; }
public virtual Store Store { get; set; }
}
//Item Mapping class
public class ItemMap : SubclassMap<Item>
{
public ItemMap()
{
Abstract();
Map(x => x.Name);
Map(x => x.Description);
Map(x => x.UnitPrice);
Map(x => x.Status);
References(x => x.Store);
}
}
The entity I have discovered has a problem (other relationship issues might exists)
//Store entity Does not inherit from EntityBase or Actuate
public class Store
{
public virtual int Id { get; set; }
public virtual int Version { get; set; }
public virtual string Name { get; set; }
public virtual IEnumerable<Item> Items { get; set; }
}
//Store mapping class
public class StoreMap : ClassMap<Store>
{
public StoreMap()
{
Id(x => x.Id).GeneratedBy.Assigned();
Version(x => x.Version);
Map(x => x.Name);
HasMany(x => x.Items);
}
}
Problem
If I try to run the following query:
//store = is the Store entity I have retrieved from the database and I am trying
//trying to return the items that are associated with the store and are active
store.Items != null && store.Items.Any(item => item.Status == ItemStatus.Active);
I get the following error:
ERROR
Nhibernate.Exceptions.GenericADOException: could not initialize a collection: [SomeDomain.Store.Items#0][SQL: SELECT items0_.StoreId as StoreId1_, items0_.Id as Id1_, items0_.Id as Id10_0_, items0_.CreatedDate as CreatedD2_10_0_, items0_.ActivatedOn as Activate1_11_0_, items0_.Name as Name12_0_, items0_.Description as Descript2_12_0_, items0_.UnitPrice as UnitPrice12_0_, items0_.Status as Status12_0_, items0_.StoreId as StoreId12_0_ FROM [Item] items0_ WHERE items0_.StoreId=?]"}
Inner Exception
"Invalid object name 'Item'."
Now, if I take out the base classes and Item doesn't inherit, and the
Id, Version
columns are part of the Item entity and are mapped in the ItemMap mapping class (with the ItemMap class inheriting from ClassMap<Item> instead, everything works without issue.
NOTE
I have also attempted to add on the StoreMap class unsuccessful.
HasMany(x => x.Items).KeyColumn("Id");
Any thoughts?

Answer 1

if entityBase is just for inheriting common properties then you do not need to map it at all
public class EntityBaseMap<TEntity> : ClassMap<TEntity> where TEntity : EntityBase
{
public EntityBaseMap()
{
Id(x => x.Id);
Version(x => x.Version);
Map(x => x.CreatedDate);
}
}
public class ActuateMap : EntityBaseMap<Actuate> { ... }
Notes:
Versionmapping should map Version property not Id
Version should be readonly in code so nobody accidently alters it
.KeyColumn("Id") is wrong because the column is from the Items table and then it's both the autogenerated id and foreign key. That's not possible nor usefull
usually only classes which are abstract should containt Abstract() in the mapping