Ruby 中的 Mysql 适配器 ActiveRecord 抛出：“数据包乱序”

Question

Ruby 版本：1.9.1 mysql版本：5.0

编写的代码是：

    require "rubygems"
    require "active_record"
    puts "1"
    class Source < ActiveRecord::Base
        puts "2"
        establish_connection(
                :adapter => "mysql",
                :host => "localhost",
                :username => "root",
                :password => "root@123",
                :database => "TrafficTracker"
            )
    end
    puts "3"
    traffic_source = Source.find(1)
    puts "4"
    puts traffic_source.source_name

上面的代码打印到 3 并在 Source.find(1) 处中断并出现错误：

1 2 3 C:/Ruby/lib/ruby/1.9.1/mysql.rb:1019:in read': Packets out of order: 0<> (RuntimeError)
from C:/Ruby/lib/ruby/1.9.1/mysql.rb:444:inread' 来自 C:/Ruby/lib/ruby/1.9.1/mysql.rb:110:in real_connect' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:600:inconnect' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:164:in initialize' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:36:innew' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:36:in mysql_connection' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:228:innew_connection' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in checkout_new_connection' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:inblock (2 级) 在 c 见鬼' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_pool.rb:186:in loop' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_pool.rb:186:inblock in checkout' 来自 C:/Ruby/lib/ruby/1.9.1/monitor.rb:201:in mon_synchronize' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_pool.rb:185:incheckout' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_pool.rb:93:in connection' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_pool.rb:316:inretrieve_connection' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_specification.rb:97:in retrieve_conn ection' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/connection_adapters/abstract/connection_specification.rb:89:inconnection' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_reco rd/base.rb:679:in columns' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/persistence.rb:284:inattributes_from_column_definition' 来自 C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/locking/optimistic.rb:62:in attributes_from_column_definition' from C:/Ruby/lib/ruby/gems/1.9.1/gems/activerecord-3.0.3/lib/active_record/base.rb:1394:ininitialize' 来自 C:/WorkspaceGunjan/TrafficTracker/TrafficTracker/TestProject/RubyPrograms/RubyPrograms/AccessTrafficTracker.rb:22:in new' from C:/WorkspaceGunjan/TrafficTracker/TrafficTracker/TestProject/RubyPrograms/RubyPrograms/AccessTrafficTracker.rb:22:in' C:\WorkspaceGunjan\TrafficTracker\TrafficTracker\TestProject\RubyPrograms\RubyPrograms> C:\WorkspaceGunjan\TrafficTracker\TrafficTracker\TestProject\RubyPrograms\RubyPrograms> C:\WorkspaceGunjan\TrafficTracker\TrafficTracker\TestProject\RubyPrograms\RubyPrograms>

在分析更多之后，我发现\Ruby\lib\ruby\1.9.1 中的mysql.rb 有问题 方法创建问题是：

def read()
      buf = []
      len = nil
      @sock.sync = false
      while len == nil or len == MAX_PACKET_LENGTH do
    a = @sock.read(4)
    len = a[0]+a[1]*256+a[2]*256*256
    pkt_nr = a[3]
    if @pkt_nr != pkt_nr then
      raise "Packets out of order: #{@pkt_nr}<>#{pkt_nr}"   #Exception raised at line number 1019
    end
    @pkt_nr = @pkt_nr + 1 & 0xff
    buf << @sock.read(len)
      end
      @sock.sync = true
      buf.join
    end

Answer 1

最后，在MySql和Postgresql上尽了全力之后，我终于可以成功连接MySql了。
工作集涉及：
红宝石版本：1.87
MySql 版本：5.5
要使用 ActiveRecord，需要安装适配器。在命令提示符下，写入：
宝石安装mysql2。

在ActiveRecord层下建立MySql数据库与Ruby连接成功的代码：

require "rubygems"
require "active_record"
class Source < ActiveRecord::Base
    set_table_name "sources"
    ActiveRecord::Base.establish_connection(
        :adapter => "mysql2",
        :host => "localhost",
        :username => "test",
        :password => "test",
        :port => 3306,
        :database => "TestDB",
        :socket => "mysql"
    )
end
source = Source.find(:first, :conditions => [ "source_id = ?", 2 ])
puts source.source_name

注意：使用的适配器是 mysql2 而不是 mysql