acts_as_tree test fails : duplicate entry # for key #

rubyonrails-talk
1

Hi, I've set up a model as follows

class EquipmentPrice < ActiveRecord::Base

  acts_as_tree :order => "id"

  ... end

which has the following db migration class CreateEquipmentPrices < ActiveRecord::Migration   def self.up     create_table :equipment_prices do |t|       t.integer :id       t.string :manufacturer       t.string :model       t.string :equipment_type       t.integer :capacity       t.integer :string_size       t.string :cost_structure       t.string :currency       t.decimal :price_each       t.decimal :price_bulk       t.integer :bulk_quantity       t.integer :parent_id

      t.timestamps     end   end

  def self.down     drop_table :equipment_prices   end end

But when I try and run the default test, I get an error message stating ActiveRecord::StatementInvalid: Mysql::Error: Duplicate entry '1' for key 1: INSERT INTO `equipment_prices` (`id`, `manufacturer`, `model`, `equipment_type`, `capacity`, `string_size`, `cost_structure`, `currency`, `price_each`, `price_bulk`, `bulk_quantity`, `parent_id`, `created_at`, `updated_at`) VALUES (1, NULL, NULL, 'PV_subsystem', NULL, NULL, NULL, 'USD', 0.0, 0.0, 1, 0, '2010-03-11 12:14:05', '2010-03-11 12:14:05')

I have read in an earlier post that this is because I have parent_id set as the primary key for the table. But when I look at the mysql table definition I see

2

resolved - it would appear that MySQL treats an int of 0 = NULL. , so my first fixture (the root of the tree) which had an id of 0 in the fixtures file, was being taken as NULL (stated as not allowed in the table definition), so set to id=1 by MySQL, then causing the 2nd fixture (id=1 in the fixtures file) to appear as a duplicate.