anchor.diff:  )
   GO
   <% end %>
  -<% object_type.attributes.each do |a|
  -    if a.reference? %>
  +<% object_type.attributes.select {|a| a.persistent? && a.reference?}.each do |a| %>
   ALTER TABLE <%= sql_qualify(object_type.schema, object_type.sql.table_name) %>
     ADD CONSTRAINT [FK_<%= object_type.name %>_<%= a.sql.column_name %>] FOREIGN KEY (<%= q(a.sql.column_name) %>)
     REFERENCES <%= sql_qualify(a.referenced_object.schema, a.referenced_object.sql.table_name) %> (<%= q(a.referenced_object.primary_key.sql.column_name) %>)
   GO
   <%
  -    end
     end
     if object_type.sql.constraints.size > 0 %><%=
       banner("Constraints for #{sql_qualify(object_type.schema, object_type.sql.table_name)}")
  
positive.code: <%= banner("DDL for Schema '#{schema.name}'") %>
  <% schema.object_types.select{|object_type| !object_type.abstract?}.each do |object_type| %>
  CREATE TABLE <%= sql_qualify(object_type.schema, object_type.sql.table_name) %>(
  <% object_type.attributes.each do |a|
  %>  <%= q(a.sql.column_name) %> <%= q(a.sql.sql_type) %> <%= a.length.nil? ? '' : "(#{a.length}) " %><%= a.sql.identity? ? 'IDENTITY(1,1) ' : '' %><%= a.nullable? ? '': 'NOT '%>NULL,
  <% end
  %>  CONSTRAINT PK_<%= object_type.name %> PRIMARY KEY <%= (object_type.sql.indexes.select{|i| i.cluster?}.size == 0) ? '' : 'NON' %>CLUSTERED (<%= q(object_type.primary_key.sql.column_name) %> ASC)
  
negative.code: GO
  <%    end
      end
     immutable_attributes = object_type.attributes.select {|a| a.persistent? && a.immutable? }
     if immutable_attributes.size > 0
      pk = object_type.primary_key
  %>
  