NHibernate mapping collection without foreign key

Question

Hi all,

I have a class called WorkingDays, this class requires a collection of dates that are the dates of bank holidays. In our database we have a table that contains these dates - I want nhibernate to get all those dates and populate the bankHolidays collection.

The catch is however I do not have a table that represents the link in the database - it seems unsecessary really when all WorkingDays impls will have the exact same list of bank holiday dates.

So how can I map this without needing to add a foreign key?
I hope the code below can ilustrate better. Thanks for any help

public class WorkingDays : Interval
{
   public ICollection<DateTime> BankHolidays
   {
       get;
       private set;
   }
}

Answer 1

Is there a reason you need this as a collection on the entity itself? Why not have a seperate repository/DAO responsible for accessing this collection? If the data were fairly static, you could probably gain quite a bit by using second level caching on this as well.

Answer 2

If you only need a read-only collection, you could try the following:

<property name="BankHolidays" type="DateTime[]" formula="(SELECT Date FROM BankHolidays)" update="false" insert="false" />