Question

首先要做的事情是：我使用的是Ruby 1.9.3和DataMapper 1.2.0。

我创建了以下看似简单的模型：

class User
    include DataMapper::Resource

    property :id,           Serial
    property :username,     String
    property :password,     BCryptHash
    property :name,         String
    property :email,        String
    property :created_at,   DateTime
end

我可以在一个irb shell中启动它，它会创建一个数据库，每个人都很开心。但后来我尝试了：

tim = User.new(:username => "tim", :password => "password", :name => "Tim", :email => "my@email.com", :created_at => Time.now)

我收到一个用户实例，可以打印到控制台并且所有属性都完好无损。我可以运行tim.save!并看到成功。但是，如果我在此时尝试列出用户，我会遇到错误：

irb(main):001:0> User.all
(Object doesn't support #inspect)
=> 
irb(main):002:0> User.first
NoMethodError: undefined method `new!' for DateTime:Class
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-do-adapter-1.2.0/lib/dm-do-adapter/adapter.rb:153:in `next!'
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-do-adapter-1.2.0/lib/dm-do-adapter/adapter.rb:153:in `block in read'
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-do-adapter-1.2.0/lib/dm-do-adapter/adapter.rb:276:in `with_connection'
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-do-adapter-1.2.0/lib/dm-do-adapter/adapter.rb:141:in `read'
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core/repository.rb:162:in `read'
    from /usr/local/Cellar/ruby/1.9.3-p0/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-core/model.rb:377:in `first'
    from (irb):5
    from /usr/local/Cellar/ruby/1.9.3-p0/bin/irb:12:in `<main>''

任何线索？由于不支持#inspect，所以没有其他任何东西真的出现在SO或Google上，而且Ruby stdlib文档明显缺少DateTime的new!方法。

Answer 1

想出这个 - 它与我使用的do_sqlite3 gem的版本有关，因为我切换到Ruby 1.9.3后没有重新安装。如this bug中所述，我需要重新安装所有do_*宝石，才能在它工作之前重新链接1.9.3。

DataMapper：无法列出对象实例和DateTime不可实例化？

1 个答案: