windows7 ruby2.0 mysql connect

$gem install mysql
  => failed, so 

$gem install ruby-mysql
  => success!

require 'mysql'

hostname = 'xxx'
username = 'xxx'
password = 'xxx'
db_name  = 'xxx'

my = Mysql.connect(hostname, username, password, db_name)
my.query("SELECT * FROM USER LIMIT 10").each do |col1, col2|
  p col1, col2
end

#=>connect & select success!