Allow specifiying attributes for NaturalId Property

[MichaelLogutov]

I want to map this simple class:

public class Country
{
    public virtual int Id { get; protected set; }
    public virtual string Code { get; protected set; }
    public virtual string Name { get; protected set; }
}

The "Code" property is actually unique so I thought to use it as natural id. But I wanted to specify the length of it. So I've created this map:

public class CountryMap : ClassMap<Country>
{
    public CountryMap ()
    {
        this.Id (x => x.Id);

        this.NaturalId ().Property (x => x.Code);
        this.Map (x => x.Code).Length (2).Unique ();

        this.Map (x => x.Name).Length (255);
    }
}

And I got this exception:
NHibernate.MappingException: Duplicate property mapping of Code found in Domain.Model.Geo.Country

The resulting HBM is this:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-access="property" auto-import="false" default-cascade="all">
  <class xmlns="urn:nhibernate-mapping-2.2" dynamic-insert="true" dynamic-update="true" mutable="false" optimistic-lock="none" name="Domain.Model.Geo.Country, Parts.Domain, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Country`">
    <cache usage="read-only" />
    <id name="Id" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Id" />
      <generator class="identity" />
    </id>
    <natural-id>
      <property name="Code" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <column name="Code" />
      </property>
    </natural-id>
    <property name="Code" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Code" length="2" unique="true" />
    </property>
    <property name="Name" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Name" length="255" />
    </property>
  </class>
</hibernate-mapping>

Packages I use:

<package id="FluentNHibernate" version="1.3.0.727" />
<package id="Iesi.Collections" version="3.2.0.4000" />
<package id="NHibernate" version="3.3.0.4000" />
<package id="NHibernate.Caches.SysCache" version="3.2.0.4000" />

[rohancragg]

I have a similar problem. After having specifiec .UseOverridesFromAssemblyOf I am then using IAutoMappingOverride. When trying to specify that a string column is a NaturalId.ReadOnly I get the same error.

[rohancragg]

It occurred to me to try using IgnoreProperty in the Override first...

This seems to prevent the error message (though the .ReadOnly() still seems not to be having the expected effect - CustomerCode column is still nullable)

public class CustomerConfigOverride: IAutoMappingOverride<Customer>
{
    public void Override(AutoMapping<Customer> mapping)
    {
        mapping.Schema("MySchema");
        mapping.IgnoreProperty(c => c.CustomerCode);
        mapping.NaturalId()
               .Property(c => c.CustomerCode)
               .ReadOnly();
...

[silversens]

Same thing here, would be great if a ".Unique" was added to ".Property"