selling_overview_monthly.rb

File.open("selling.csv","w") do |f| 
  f.write("selling_key;selling_value;order_id;order_date;order_state;order_product\n")
  f.write(
    ConcernExtensionEntry.where(:value => %w[0 1]).
      where("created_at > ?", Date.new(2018,1,31).end_of_day).
      where("created_at < ?", Date.new(2018,4,1).beginning_of_day).
      where("`key` LIKE ?", "selling_%").
      map do |ce| 
        t = Tenancy.find(ce.target_id)
        "#{ce.key};#{ce.value};#{t.id};#{t.updated_at};#{t.state};#{t.product}"
      end.
      join("\n")
  )
end