nhibernate - disable automatic\lazy loading of child records for one to many relationsihps

Question

I would like to know if there is a way to disable automatic loading of child records in nHibernate ( for one:many relationships ).

We can easily switch off lazy loading

Answer 1

Given your request, you could simply not map from Department to Employees, nor have an Employees property on your department. This would mean you always have to make a database hit to find the employees of a database.

Aplogies if these code examples don't work out of the box, I'm not near a compiler at the moment

So, your department class might look like:

 public class Department 
 { 
     public int Id { get; protected set; }
     public string Name { get; set; }
     /* Equality and GetHashCode here */
 }

and your Employee would look like:

 public class Employee
 { 
     public int Id { get; protected set; }
     public Name Name { get; set; }
     public Department Department { get; set; }
     /* Equality and GetHashCode here */
 }

Any time you wanted to find Employees for a department, you've have to call:

/*...*/
session.CreateCriteria(typeof(Employee))
    .Add(Restrictions.Eq("Department", department)
    .List();

Simply because your spec says "Departments have many Employees", doesn't mean you have to map it as a bi-directional association. If you can keep your associated uni-directional, you can really get your data-access to fly too.

Google "Domain Driven Design" Aggregate, or see Page 125 of Eric Evan's book on Domain Driven Design for more information