Mapping a many-to-many relationship as an IDictionary

I am trying to map a Person and Address class that have a many-to-many relationship. I want to map the Address collection as an IDictionary with the Address property Type as the key. The relationship is only mapped fro开发者_C百科m the Person side.

public class Person
{
    public IDictionary<int, Address> Addresses { get; set; }
}

public class Address
{
    public int Type { get; set; }
}

The mapping I am using is:

HasManyToMany<Address>(x => x.Addresses).Table("PersonAddress")
    .ParentKeyColumn("PersonId").ChildKeyColumn("AddressId")
    .AsMap(x => x.Type);

The problem is that the SQL issued is:

SELECT addressesd0_.PersonId    as PersonId1_,
   addressesd0_.AddressId       as AddressId1_,
   addressesd0_.Type            as Type1_,
   address1_.AddressId          as AddressId5_0_
   -- etc.
FROM   dbo.PersonAddress addressesd0_
   left outer join dbo.Address address1_
     on addressesd0_.AddressId = address1_.AddressId
WHERE  addressesd0_.PersonId = 420893

It's attempting to select Type from the many-to-many join table, which doesn't exist. I've tried a number of variations of the mapping without success.

How can I map this?

It's not possible. Dictionaries need a key value in the relational table. The table structure you have is a simple many-to-many bag or set.

What I would do, is map it as a normal bag or set and provide dictionary like access in the entity:

public class Person
{
    private IList<Address> addresses;

    public IEnumerable<Address> Addresses { get { return addresses; } }

    public Address GetAddressOfType(int addressType)
    {
      return addresses.FirstOrDefault(x => x.Type == addressType);
    }

    public void SetAddress(Address address)
    {
      var existing = GetAddressOfType(address.Type);
      if (existing != null)
      {
        addresses.Remove(existing);
      }
      addresses.Add(address);
    }
}

You need to use components:

HasMany<Address>(x => x.Addresses) 
               .AsMap<int>("FieldKey")  
               .Component(x => x.Map(c => c.Id));