Question

I’m trying to use Datamapper in my Rails 3.1 application and I’m having trouble mapping models that exist on a 2nd repository.

I have the following class

class Arp
  include DataMapper::Resource

  storage_names[:passive] = "arp"

  property :id, Serial, :field => "id"
  property :ip_address, String, :field => "ipaddr"

  def self.default_repository_name
    :passive
  end
end

There are some more fields but for the sake of simplicity I commented them out and got the same error. Here’s what I get when i run rake db:migrate:

Arp must have at least one property or many to one relationship to be valid

Not sure what’s going on because I clearly have a property defined.

Here’s the table sttucture from mysql

+--------+-------------+------+-----+---------+----------------+
| Field  | Type        | Null | Key | Default | Extra          |
+--------+-------------+------+-----+---------+----------------+
| id     | int(11)     | NO   | PRI | NULL    | auto_increment |
| ipaddr | varchar(15) | NO   |     | NULL    |                |
+--------+-------------+------+-----+---------+----------------+

Again a few fields removed for clarity.

I have the multiple repositories in my database.yml file in rails and I set them up based on the guide on the dm-rails github page.

Here’s a shortened version of that file.

passive_defaults: &passive_defaults
  adapter: mysql
  username: <USERNAME GOES HERE>
  password: <PASSWORD GOES HERE>
  host: localhost
  database: passive

development:
  database: portal
  <<: *portal_defaults
  repositories: 
    passive: 
      <<: *passive_defaults

Anyone see what I’m doing wrong here? Thanks.

Answer 1

I solved this shortly after asking the question.

The order of the self.default_repository_name override mattered. So

class Arp
  include DataMapper::Resource

  def self.default_repository_name
    :passive
  end    
  storage_names[:passive] = "arp"

  property :id, Serial, :field => "id"
  property :ip_address, String, :field => "ipaddr"    
end

works.