ruby 连接 mysql

require "rubygems"
require "mysql"
?? begin
???? dbh = Mysql.real_connect("localhost", "root", "", "test")
???? res = dbh.query("SELECT * FROM card")
#???? while row = res.fetch_array do
#???? printf "%s, %s\n", row["card_id"], row[1]
#???? end

? res.each_hash do |f|print "#{f['card_id']} -- #{f['card_info']}\n"end
?
??? puts "Server version: " + dbh.get_server_info
??? rescue Mysql::Error => e
???? puts "Error code: #{e.errno}"
???? puts "Error message: #{e.error}"
???? puts "Error SQLSTATE: #{e.sqlstate}" if e.respond_to?("sqlstate")
?? ensure
???? dbh.close if dbh
?? end