FluentNHibernate: Automapping OneToMany relation using attribute and convention - nhibernate

Question

This is very similar to my previous question: FluentNHibernate: How to translate HasMany(x => x.Addresses).KeyColumn("PersonId") into automapping
Say I have these models:
public class Person
{
public virtual int Id { get; private set; }
public virtual ICollection<Address> Addresses { get; private set; }
}
public class Address
{
public virtual int Id { get; private set; }
public virtual Person Owner { get; set; }
}
I want FluentNHibernate to create the following tables:
Person
PersonId
Address
AddressId
OwnerId
This can be easily achieved by using fluent mapping:
public class PersonMapping : ClassMap<Person>
{
public PersonMapping()
{
Id(x => x.Id).Column("PersonId");
HasMany(x => x.Addresses).KeyColumn("OwnerId");
}
}
public class AddressMapping : ClassMap<Address>
{
public AddressMapping()
{
Id(x => x.Id).Column("AddressId");
References(x => x.Person).Column("OwnerId");
}
}
I want to get the same result by using auto mapping. I tried the following conventions:
class PrimaryKeyNameConvention : IIdConvention
{
public void Apply(IIdentityInstance instance)
{
instance.Column(instance.EntityType.Name + "Id");
}
}
class ReferenceNameConvention : IReferenceConvention
{
public void Apply(IManyToOneInstance instance)
{
instance.Column(string.Format("{0}Id", instance.Name));
}
}
// Copied from #Fourth: https://stackoverflow.com/questions/6091290/fluentnhibernate-how-to-translate-hasmanyx-x-addresses-keycolumnpersonid/6091307#6091307
public class SimpleForeignKeyConvention : ForeignKeyConvention
{
protected override string GetKeyName(Member property, Type type)
{
if(property == null)
return type.Name + "Id";
return property.Name + "Id";
}
}
But it created the following tables:
Person
PersonId
Address
AddressId
OwnerId
PersonId // this column should not exist
So I added a AutoMappingOverride:
public class PersonMappingOverride : IAutoMappingOverride<Person>
{
public void Override(AutoMapping<Person> mapping)
{
mapping.HasMany(x => x.Addresses).KeyColumn("OwnerId");
}
}
This correctly solved the problem. But I want to get the same result using attribute & convention. I tried:
public class Person
{
public virtual int Id { get; private set; }
[KeyColumn("OwnerId")]
public virtual ICollection<Address> Addresses { get; private set; }
}
class KeyColumnAttribute : Attribute
{
public readonly string Name;
public KeyColumnAttribute(string name)
{
Name = name;
}
}
class KeyColumnConvention: IHasManyConvention
{
public void Apply(IOneToManyCollectionInstance instance)
{
var keyColumnAttribute = (KeyColumnAttribute)Attribute.GetCustomAttribute(instance.Member, typeof(KeyColumnAttribute));
if (keyColumnAttribute != null)
{
instance.Key.Column(keyColumnAttribute.Name);
}
}
}
But it created these tables:
Person
PersonId
Address
AddressId
OwnerId
PersonId // this column should not exist
Below is the rest of my code:
ISessionFactory sessionFactory = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ConnectionString(connectionString))
.Mappings(m =>
m.AutoMappings.Add(AutoMap.Assemblies(typeof(Person).Assembly)
.Conventions.Add(typeof(PrimaryKeyNameConvention))
.Conventions.Add(typeof(PrimaryKeyNameConvention))
.Conventions.Add(typeof(ReferenceNameConvention))
.Conventions.Add(typeof(SimpleForeignKeyConvention))
.Conventions.Add(typeof(KeyColumnConvention)))
//m.FluentMappings
// .Add(typeof (PersonMapping))
// .Add(typeof (AddressMapping))
)
.ExposeConfiguration(BuildSchema)
.BuildConfiguration()
.BuildSessionFactory();
Any ideas? Thanks.
Update:
The test project can be downloaded from here.

Answer 1

Sigh... Learning NHibernate is really a hair pulling experience.
Anyway I think I finally figured out how to solve this problem: Just remove the SimpleForeignKeyConvention and everything will work fine.
It seems the SimpleForeignKeyConvention conflicts with both ReferenceKeyConvention & KeyColumnConvention. It has higher priority than KeyColumnConvention but lower priority than ReferenceKeyConvention.
public class SimpleForeignKeyConvention : ForeignKeyConvention
{
protected override string GetKeyName(Member property, Type type)
{
if(property == null)
// This line will disable `KeyColumnConvention`
return type.Name + "Id";
// This line has no effect when `ReferenceKeyConvention` is enabled.
return property.Name + "Id";
}
}

Answer 2

I've tested your classes with FHN's auto-mapping feature and it does not create that second PersonId on Address table.
I'm using FHN v1.2.0.721 from here