Question

我不想在这里问一栏我的模式:

require  rubygems 
require  dm-core 
require  dm-migrations 
require  dm-aggregates 

db_name =  mydb.sqlite 

DataMapper::Logger.new($stdout, :debug)
DataMapper.setup(:default,  sqlite://  + Dir.pwd +  /  + db_name)

class Context
  include DataMapper::Resource
  property :id,         Serial
  property :order,      Integer

  def initialize
    self.order = (self.class.max(:order) || 0) + 1
  end

  def move_up
    temp = self.class.first(:order => (self.order - 1))
    temp.order += 1
    temp.save
    self.order -= 1
    self.save
  end

end

DataMapper.finalize
DataMapper.auto_upgrade!

但是,在我称之为<代码>move_up<>/code>方法时,我会发现以下错误。

Failure/Error: context2.move_up
+options[:order]+ entry 1 of an unsupported object Fixnum
# ./context.rb:11:in `move_up

尽管存在一些条件,但为什么不从事这项工作?

Answer 1

:顺序是保留词,因为它是你可以选择的一个选项。仅将其重新命名为不同之处,它将发挥作用。

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