NH 3.3 Composite-ID mapping by code

Question

I am pulling my hair out here trying to figure out how to map the UsersRoles table listed below. I don't look good bald so please help :)

//Here is the Entity

public class UsersRole
{
    public UsersRole() { }
    public virtual User User { get; set; }
    public virtual Role Role { get; set; }
    public virtual System.Guid UserId { get; set; }
    public virtual System.Guid RoleId { get; set; }


}

//Here is the mapping so far

public class UsersRoleMap : ClassMapping<UsersRole>
{
    public UsersRoleMap()
    {
        Table("UsersRoles");
        Lazy(true);

       // ComponentAsId(); How does this work??


        Property(x => x.UserId, map => map.Column(c =>
            {
                c.Name("UserId");
                c.NotNullable(true);
                c.Length(30);
                c.SqlType("uniqueidentifier");
            }));
        Property(x => x.RoleId, map => map.Column(c =>
            {
                c.Name("RoleId");
                c.NotNullable(true);
                c.Length(30);
                c.SqlType("uniqueidentifier");
            }));
    }
}

Please see the comment in the mapping for ComponentAsId

Thanks in advance if someone can get me on the right track

Answer 1

The method you are looking for is called ComposedId:

public class UsersRoleMap : ClassMapping<UsersRole>
{
    public UsersRoleMap()
    {
        ComposedId(map => 
        {
            map.Property(x => x.UserId);
            map.Property(x => x.RoleId);
        });
    }
}

Answering to your question about how ComponentAsId works. You should have following classes to use ComponentAsId method

public class UsersRoleId
{
    public System.Guid UserId { get; set; }
    public System.Guid RoleId { get; set; }
}

public class UsersRole
{
    public virtual User User { get; set; }
    public virtual Role Role { get; set; }
    public virtual UsersRoleId Id { get; set; }
}

And now you could map UsersRole.Id as ComponentAsId

public class UsersRoleMap : ClassMapping<UsersRole>
{
    public UsersRoleMap()
    {
        ComponentAsId(x => x.Id);
    }
}

PS: Why you need to map UsersRoles table? I would suggest you to map users to roles as many-to-many relation.

public class UsersMap : ClassMapping<User>
{
    public UsersMap()
    {
        Set(x => x.Roles, x => { }, x => x.ManyToMany());
    }
}

public class RolesMap : ClassMapping<Role>
{
    public RolesMap()
    {
        Set(x => x.Users, x => { }, x => x.ManyToMany());
    }
}