extract_fixtures.rb

def extract_fixtures(dirname)
  sql  = "SELECT * FROM %s"
  skip_tables = ["schema_info"]
  ActiveRecord::Base.establish_connection
  (ActiveRecord::Base.connection.tables - skip_tables).each do |table_name|
    extract_fixture_from table_name, "#{dirname}/#{table_name}.yml"
  end
end

def extract_fixture_from(table_name, filename)
  sql  = "SELECT * FROM %s"
  ActiveRecord::Base.establish_connection
  File.open(filename, 'w') do |file|
    i='000'
    data = ActiveRecord::Base.connection.select_all(sql % table_name)
    file.write data.inject({}) { |hash, record|
      hash["#{table_name}_#{i.succ!}"] = record
      hash
    }.to_yaml
  end
end

namespace :db do
  namespace :fixtures do
    namespace :spec do
      desc 'Create YAML spec fixtures from data in an existing database.  
      Defaults to development database.  Set RAILS_ENV to override.'

      task :extract_all => :environment do
        extract_fixtures("#{RAILS_ROOT}/spec/fixtures")
      end
  
    end

    namespace :test do
      desc 'Create YAML test fixtures from data in an existing database.  
      Defaults to development database.  Set RAILS_ENV to override.'

      task :extract_all => :environment do
        extract_fixtures("#{RAILS_ROOT}/test/fixtures")
      end
    end

    desc 'Create YAML file from data in an existing database.
    Set TABLE_NAME and FILENAME environments.'
    task :extract_from => :environment do
      extract_fixture_from ENV['TABLE_NAME'], ENV['FILENAME']
    end
  end
end