Question

I have 3 tables Users, AccessLevels, Roles. My User class have public virtual Dictionary<Role,AccessLevel> Roles {get; set;}, and
Role class have public virtual Dictionary<User,AccessLevel> Users {get;set;} ? How such dictionaries should be represented in the mapping?

Answer 1

in FluentNhibernate it would look like

HasManyToMany(user => user.Roles)
    .Table("UserRoleAccessLevel")
    .AsEntityMap("role_id")
    .KeyColumn("user_id");

HasManyToMany(role => role.Users)
    .Table("UserRoleAccessLevel")
    .AsEntityMap("user_id")
    .KeyColumn("role_id");

can’t test it right now though

Update: in hbm.xml

<map name="Roles" table="UserRoleAccessLevel">
  <key column="user_id" />
  <index-many-to-many class="Role" column="role_id" />
  <many-to-many class="AccessLevel" column="accesslevel_id" />
</map>

<map name="Users" table="UserRoleAccessLevel">
  <key column="role_id" />
  <index-many-to-many class="User" column="user_id" />
  <many-to-many class="AccessLevel" column="accesslevel_id" />
</map>