Question

嗨大家我用mongomapper运行sinatra应用程序。我有一些名为Movie（Document）和Cover（EmbeddedDocument）的模型。我使用

将封面嵌入到电影中

@movie.covers << @cover
@movie.save

这很有效。当点击@ movies.covers时，我得到了一系列嵌入式文档。但我无法破坏嵌入式文档。我试过这样的事情

@movie.covers.each do |c|
c.destroy
end

NoMethodError: undefined method `destroy' for #<Cover:0xb7b20734>
 from (irb):5
 from /usr/lib/ruby/gems/1.8/gems/mongo_mapper-0.6.8/lib/mongo_mapper/associations/proxy.rb:85:in `call'
 from /usr/lib/ruby/gems/1.8/gems/mongo_mapper-0.6.8/lib/mongo_mapper/associations/proxy.rb:85:in `method_missing'
 from /usr/lib/ruby/gems/1.8/gems/mongo_mapper-0.6.8/lib/mongo_mapper/associations/proxy.rb:85:in `each'
 from /usr/lib/ruby/gems/1.8/gems/mongo_mapper-0.6.8/lib/mongo_mapper/associations/proxy.rb:85:in `send'
 from /usr/lib/ruby/gems/1.8/gems/mongo_mapper-0.6.8/lib/mongo_mapper/associations/proxy.rb:85:in `method_missing'
 from (irb):4
 from :0

任何人都可以如何摧毁它吗？如果有人启发我如何更新嵌入式文档，那就太好了。

Answer 1

封面存储为电影对象中的数组，因此您可以执行以下操作：

@movie.covers.clear
@movie.save

或者如果你想要有选择性

@movie.covers.delete_if {|cover| cover.name == "bla"}
@movie.save

Answer 2

如果您根据名称等属性进行删除，但是如果您已经知道了ID并想删除它，则可以使用p-rob's tubmlr post中的这个技巧：

def destroy
@phone_number = @person.phone_numbers.find(params[:id])
@person.phone_numbers.delete_if{|phone_number| phone_number.id == @phone_number.id}
if @person.save
redirect_to @person
  else
    flash[:error] = "dag, yo."
  end
end

我真的很挣扎:(

Answer 3

这是一个quick and dirty complete gist，用于从关联中删除嵌入的文档。在这里重复：

class Period
  include MongoMapper::EmbeddedDocument

  key :text, String

  embedded_in :schedule

  def to_s
    text
  end

end

class Schedule
  include MongoMapper::Document

  key :name, String

  many :periods

  def to_s
    text = "#{name}, periods: " + periods.join(', ')
  end

end

s1 = Schedule.create(:name => "Thursday",
  :periods => [
    Period.new(:text => "Morning"),
    Period.new(:text => "Afternoon"),
    Period.new(:text => "Evening")
  ])
puts s1
#Thursday, periods: Morning, Afternoon, Evening

s1.periods.delete_if{|p| p.text == 'Afternoon'}
s1.save
puts s1
# Thursday, periods: Morning, Evening

如何删除mongomapper中的嵌入文档？

3 个答案: