when 'sqlite'
      sequel.gsub!(/!DB_DEVELOPMENT!/,"\"sqlite://db/#{db}_development.db\"")
      sequel.gsub!(/!DB_PRODUCTION!/, "\"sqlite://db/#{db}_production.db\"")
      sequel.gsub!(/!DB_TEST!/,       "\"sqlite://db/#{db}_test.db\"")
      require_dependencies 'sqlite3'