未定义的方法'eq'的nil：NilClass与Ubuntu 3上的Rails 3和Ruby企业

Question

我不确定是什么原因导致此错误，但是由于我在乘客中以及现在在控制台中都遇到了此问题，所以我想也许是MySQL驱动程序出了问题？一切都按预期在osx /
10.6上运行。它只是不会在Ubuntu 8.04 Hardy上使用。

我将问题确定为“销毁”方法，或者直接调用activerecord实例的方法。为什么会这样呢？有任何想法吗？

系统：

• Ubuntu 8.04 Hardy。
• ruby 1.8.7（2010-04-19补丁程序级别253）[i686-linux]，MBARI 0x8770，Ruby Enterprise Edition 2010.02
• 导轨3.0.0-beta4
• 适用于使用readline 5.2的debian-linux-gnu（i486）的mysql Ver 14.12 Distrib 5.0.51a

这是错误输出

root@gehege:/var/www/foobar.com/api.foobar.com/v1# rake cleanup:status_cleanup RAILS_ENV=production --trace
(in /var/www/foobar.com/api.foobar.com/v1)
** Invoke cleanup:status_cleanup (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute cleanup:status_cleanup
rake aborted!
undefined method `eq' for nil:NilClass
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/persistence.rb:76:in `destroy'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/locking/optimistic.rb:110:in `destroy'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/callbacks.rb:278:in `destroy'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activesupport-3.0.0.beta4/lib/active_support/callbacks.rb:412:in `_run_destroy_callbacks'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/callbacks.rb:278:in `destroy'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/transactions.rb:230:in `destroy'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/transactions.rb:287:in `with_transaction_returning_status'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:139:in `transaction'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/transactions.rb:202:in `transaction'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/transactions.rb:285:in `with_transaction_returning_status'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/activerecord-3.0.0.beta4/lib/active_record/transactions.rb:230:in `destroy'
/var/www/foobar.com/api.foobar.com/v1/lib/tasks/cleanup.rake:8
/var/www/foobar.com/api.foobar.com/v1/lib/tasks/cleanup.rake:6:in `each'
/var/www/foobar.com/api.foobar.com/v1/lib/tasks/cleanup.rake:6
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
/opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31
/opt/ree/bin/rake:19:in `load'
/opt/ree/bin/rake:19

编辑：

即使在运行apt-get更新/升级到最新的强壮软件包并重新编译ree和mysql gem之后，我仍然遇到相同的错误。

Answer 1

回答我自己的问题：经过研究，我发现rails（activerecord）在映射到模型的表上需要id字段。如果使用链接表，则不需要它们-
但是对于要作为模型进行处理的表，则是必需的。就我而言，解决方案是添加

set_primary_key :cal_id

其中，cal_id是我的唯一密钥。