private void CreateForeignKeyProp(IRelationshipDef relationshipDef)
{
var relationshipName = relationshipDef.RelationshipName;
var propertyName = PropNamingConvention.GetSingleRelOwningPropName(relationshipName);
var propDef = new PropDef(propertyName, typeof (Guid?), PropReadWriteRule.ReadWrite, null)
{
Compulsory = relationshipDef.IsCompulsory
};
SetDatabaseFieldName(propDef, relationshipName);
this.ClassDef.PropDefcol.Add(propDef);
}