# File lib/og/meta.rb, line 117
        def has_one(name, klass = nil, options = {})

                # linkback is the property of the child object that 'links back' 
                # to this object. 

                linkback = options[:linkback] || "#{MetaUtils.expand(self)}_oid"
                
                meta :has, [klass, linkback]
                
                module_eval %{
                        def #{name}(extrasql = nil)
                                Og.db.select_one("SELECT * FROM #{Backend.table(klass)} WHERE #{linkback}=\#\@oid \#\{extrasql\}", #{klass})
                        end

                        def delete_#{name}(extrasql = nil)
                                Og.db.exec("DELETE FROM #{Backend.table(klass)} WHERE #{linkback}=\#\@oid \#\{extrasql\}") 
                        end                  
                }
        end