How to setup Fluent NHibernate Many-To-Many automapping using Set instead of Bag?

Question

http://www.codinginstinct.com/2010/03/nhibernate-tip-use-set-for-many-to-many.html

I want to do the way the author suggested for fluent nhibernate many-to-many but use automapping instead of HBM file.

Here are my two entities

 public class User
    {
        public virtual int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual Iesi.Collections.Generic.Set<City> Cities { get; set; }

}

 public class City{
        public virtual int Id { get; set; }
        public virtual string Name { get; set; }
        public virtual Iesi.Collections.Generic.Set<User> Users { get; set; }

}

Tried with HashSet, IList, and Set. But when I looked at the HBM files generated by calling automapping output method:

 var autoMappings = new AutoPersistenceModel().AddEntityAssembly(entityAssembly).Where(x => x.Namespace.EndsWith("Domain"));

autoMappings.WriteMappingsTo((@"C:\TEMP");

It's still bag type

<bag inverse="true" name="Users" table="MNUserCity" mutable="true">
      <key>
        <column name="CityId" />
      </key>
      <many-to-many class="MyApp.Entity.Domain.User, MyApp.Entity, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null">
        <column name="UserId" />
      </many-to-many>
    </bag>

Is there any conventions/override I can use in Fluent NHibernate to alter the collection type for all the ManyToMany in the app domain? I looked at IHasManyToMany convention but no clue.

Anyone can help? Thanks.

BTW, I'm using latest build in http://github.com/jagregory/fluent-nhibernate

nulltoken nulltoken · Accepted Answer · 2011-01-26T11:06:59

Changing the type of Users and Cities from Set to ISet should solve your issue.

As stated by James in this thread, "The automapper is very opinionated and inflexible, and it expects collections to be exposed as IList or ISet."

How to setup Fluent NHibernate Many-To-Many automapping using Set instead of Bag?

1 Answers