Import from Canadian food db to SQL using ruby

importer.rb

#http://erikonrails.snowedin.net/?p=212
desc "Imports a CSV file into an ActiveRecord table"
task :csv_model_import, :source, :model, :needs => :environment do |task,args|

  def import_csv(classname, options = {})
    lines = File.new(options[:filename]).readlines
    header = lines.shift.strip
    keys = header.split(',')

    model = Module.const_get(classname)

    lines.each do |line|
      params = {}
      values = line.strip.split(',')
      keys.each_with_index do |key,i|
        continue unless options[:fields].has_key? key
        params[options[:fields][key]] = values[i]
      end
      model.create(params)
    end
  end

  if args[:source] == 'CND'
    #Model list is ordered by import.
    models = {
      'FoodGroup' => {
        :filename => 'FOOD_GRP.txt',
        :fields => {
          :FD_GRP_ID => :id,
          :FD_GRP_NME => :name,
          :FD_GRP_COD => :code
        }
      },
      'FoodSource' => {
        :filename => 'FOOD_SRC.txt',
        :fields => {
          :FD_SRC_ID => :id,
          :FD_SRC_COD => :code,
          :FD_SRC_NME => :name
        }
      },
      'FoodMeasure' => {
        :filename => 'MEASURE.txt',
        :fields => {
          :MSR_ID => :id,
          :MSR_NME => :name
        }
      },
      'FoodNutrient' => {
        :filename => 'NT_NM.txt',
        :fields => {
          :NT_ID => :id,
          :NT_COD => :code,
          :NT_SYM => :symbol,
          :UNIT => :unit,
          :NT_NME => :name,
          :TAGNAME => :tagname
        }
      },
      'FoodYield' => {
        :filename => 'YLD_NM.txt',
        :fields => {
          :YLD_ID => :id,
          :YLD_NAME => :name
        }
      },
      'FoodRefuse' => {
        :filename => 'REFU_NM.txt',
        :fields => {
          :REFUSE_ID => :id,
          :REFUSE_NME => :name
        } 
      },
      'FoodNutrientSource' => {
        :filename => 'NT_SRC.txt',
        :fields => {
          :NT_SRC_ID => :id,
          :NT_SRC_COD => :code,
          :NT_SRC_NME => :name
        }
      },
      'FoodNutrient' => {
        :filename => 'NT_NM.txt',
        :fields => {
          :NT_ID => :id,
          :NT_COD => :code,
          :NT_SYM => :symbol,
          :UNIT => :unit,
          :NT_NME => :name,
          :NT_TAGNAME => :tagname
        }
      },
      #These depends on Foods and the previous enumerations
      'Foods' => {
        :filename => 'FOOD_NM.txt',
        :fields => {
          :FD_ID => :id,
          :FD_CODE => :code,
          :FD_GRP_ID => :food_group_id,
          :FD_SRC_ID => :food_source_id,
          
          :L_FD_NME => :name
        }
      },
      'FoodNutrientAmount' => 'NT_AMT.txt',
      'FoodsYields' => 'YIELD.txt',
      'FoodsRefuses' => 'REFUSE.txt',
      'FoodConversion' => 'CONV_FAC.txt'
    }

    if args[:model] == 'all'
      models.each do |model,filename|
        import_csv model, options
      end
    else
      filename = models[args[:model]]
      import_csv args[:model], options
    end
  end
end