思った以上に簡単にかけた便利コマンド

sql2csv.rb

require 'csv'
require 'sequel'

def sql_to_csv(sql, db: Sequel.connect(ENV['DATABASE_URL']))
  rel = db[sql]

  CSV.generate('', force_quotes: ENV['NO_QUOTE'].nil?) do |csv|
    csv << rel.columns
    rel.each {|row| csv << row.values }
  end
end

if $0 == __FILE__
  puts sql_to_csv(ARGF.read)
end