From: darius <noone@...>
Date: 2007-11-11T02:30:03+09:00
Subject: why this rake db:migrate error

hello

I'm getting a rake db:migrate error which I can't understand (newbie).

-- add_column(:stories, :votes_count, :integer, {:default=>0})
rake aborted!
Mysql::Error: #42S21Duplicate column name 'votes_count': ALTER TABLE 
stories ADD
 `votes_count` int(11) DEFAULT 0

(See full trace by running task with --trace)

the error is in

005_add_counter_cache_to_stories.rb

class AddCounterCacheToStories < ActiveRecord::Migration
	add_column :stories, :votes_count, :integer, :default => 0
	def self.up
		Story.find(:all).each do |s|			
		s.update_attribute :votes_count, s.votes.length			
		end		
	end
	
	def self.down		
		remove_column :stories, :votes_count		
	end
end

the latest migration file is

006_add_story_creation_date_and_description.rb

class AddStoryCreationDateAndDescription < ActiveRecord::Migration
	def self.up
		add_column :stories, :created_at, :datetime		
		add_column :stories, :description, :text		
	end
	
	def self.down		
		remove_column :stories, :created_at		
		remove_column :stories, :description		
	end	
end

here's schema.db, which I have not touched

ActiveRecord::Schema.define(:version => 5) do

  create_table "stories", :force => true do |t|
    t.column "name",        :string
    t.column "link",        :string
    t.column "permalink",   :string
    t.column "user_id",     :integer
    t.column "votes_count", :integer, :default => 0
  end

  create_table "users", :force => true do |t|
    t.column "login",    :string
    t.column "password", :string
    t.column "name",     :string
    t.column "email",    :string
  end

  create_table "votes", :force => true do |t|
    t.column "story_id",   :integer
    t.column "created_at", :datetime
    t.column "user_id",    :integer
  end

end

(if this looks familiar, it's b/c I'm working through the examples in a 
RoR book)

In an earlier migration file (003) I also have an add_column but rake 
doesn't give me an error.  That add_column however does not have a 
default value option.

any help is appreciated.  thanks in advance.