Mapping enumerations

An improperly mapped enumeration can lead to unnecessary updates. In this recipe, we'll discuss why and show you how to map an enumeration property to a string field.

How to do it…

1. Add a new folder named Enumerations to the MappingRecipes project.

2. Add the following AccountTypes enum to the folder:

   public enum AccountTypes
   {
     Consumer,
     Business,
     Corporate,
     NonProfit
   }

3. Add the following Account class:

   public class Account
   {  
     public virtual Guid Id { get; set; }
     public virtual AccountTypes AcctType { get; set; }
     public virtual string Number { get; set; }
     public virtual string Name { get; set; }
   }

4. Add an embedded NHibernate mapping document named Account.hbm.xml with the following class mapping:

   <class name="Account">
     <id name="Id">
       <generator class="guid.comb" />
     </id>
     <natural-id>
       <property name="Number" not-null="true"  />
     </natural-id>
     <property name="Name" not-null="true" />
     <property name...