How to map dictionary with element referencing dictionary key?

[Filip Kinsky]

I'd like to map following classes, but I'm not able to figure out how to define the mappings (I'm using mapping by code):

public class Employee : EntityBase

{

public virtual string FirstName { get; protected set; }

public virtual string LastName { get; protected set; }

public virtual string EmpNumber { get; protected set; }

public virtual IDictionary<Month, Salary> Salaries { get; protected set; }

}

public class Salary

{

public virtual Month Month { get; protected set; }

public virtual decimal Amount { get; set; }

}

public class Month

{

public virtual int Year { get; protected set; }

public virtual int MonthNumber { get; protected set; }

}

The problem is I can't get Salary.Month mapped, because Month is also the key of Employee.Salaries dictionary. If I try to map the Month using following mapping code I get NHibernate.MappingException : Repeated column in mapping for collection: Employee.Salaries column: Year.

mapper.Class<Employee>(ca =>

                      {

         ca.Id(x => x.Id);

         ca.Property(x => x.FirstName, m => m.UniqueNotNull());

         ca.Property(x => x.LastName, m => m.NotNullable(true));

         ca.Property(x => x.EmpNumber, m => m.NotNullable(true));

         ca.ManyToOne(x => x.User, m => m.NotNullable(true));

        ca.Map(x => x.Salaries,

              m =>

              {

              m.Key(x => x.Column("EMPLOYEE_ID"));

              m.Table("EMPSALARIES");

              },

              m => m.Component(c =>

                                {

                                c.Property(x => x.Year);

                                c.Property(x => x.MonthNumber);

                                }),

              m => m.Component(c =>

                                {

                                c.Property(x => x.Amount);

                                c.Component(x => x.Month,

                                           x =>

                                            {

                                            x.Property(xx => xx.Year);

                                            x.Property(xx => xx.MonthNumber);

                                            });

                                }));

                      });

I was also trying to map the month as a component explicitely using mapper.Component() and than mapping Sallaries without specifying any key and element mapping, but result was just the same. Is there any trick how to achieve this?

[Fabio Maulo]

c.Property(x => x.Year, map=> map.Column("KeyYear"));

c.Property(x => x.MonthNumber, map=> map.Column("KeyMonth"));

[Filip Kinsky]

Thanks for your reply, Fabio. It unfortunately looks like there's no solution to map this dictionary and not to duplicate month+year columns in underlying DB table, which was my aim ;(