小编rah*_*hum的帖子

尝试DRY,我试图在对象初始化后分配给模型的实例变量.

class WorkNote < ActiveRecord::Base

  def after_initialize
    self[:clockin]= WorkNote.last_clockout
  end

  def self.last_clockout
    WorkNote.find(:first, :order => "clockout DESC").clockout
  end
end

但是,方法调用after_initialize会导致SystemStackError:

ActiveRecord::StatementInvalid: SystemStackError: stack level too deep: SELECT * FROM "work_notes"  ORDER BY clockout DESC LIMIT 1
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract_adapter.rb:212:in `log'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/sqlite_adapter.rb:157:in `execute'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/sqlite_adapter.rb:402:in `catch_schema_changes'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/sqlite_adapter.rb:157:in `execute'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/sqlite_adapter.rb:305:in `select'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all_without_query_cache'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/abstract/query_cache.rb:62:in `select_all'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:661:in `find_by_sql'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:1553:in `find_every'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:1510:in `find_initial'
    from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/base.rb:613:in `find'
    from /Users/noob/jobs/app/models/work_note.rb:10:in `last_clockout'
    from /Users/noob/jobs/app/models/work_note.rb:6:in `after_initialize'
    from …