import-csv.rake

namespace :db do
  desc "load data from csv"
  task :load_csv_data  => :environment do
    require 'fastercsv'

    FasterCSV.foreach("importdata/tarife.csv", :headers => true, :col_sep => ',') do |row|
      Anbieter.find_or_create_by_name(
        :name    => row['Anbieter_Name']
        :hotline => row['Hotline'],
        :email   => row['Email']
        )

      associated_anbieter  = Anbieter.find_by_name(row['Anbieter_Name'])
      associated_kategorie = Kategorie.find_by_name(row['Kategorie'])     
      associated_netz      = Netz.find_by_name(row['Netz'])

      Tarif.create( 
        :anbieter_id  => associated_anbieter.id,
        :kategorie_id => associated_kategorie.id, 
        :netz_id      => associated_netz.id,      
        :name         => row['Tarif_Name']
        )
    end
  end
end

Yea I got it to work. Thanks again for the code.