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如何删除MongoMapper中的嵌入文档?

mongomapper sinatra ruby-on-rails

8

Deepak · 技术社区 · 16 年前

嗨,伙计们,我用MongoMapper运行了一个Sinatra应用程序。我有一个叫做电影(文档)和封面(嵌入文档)的模型。

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

这很管用。当hit@movies.covers时,我得到了一系列嵌入的文档。但我无法销毁嵌入的文档。我试过这样的东西

@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

有人能告诉我怎么销毁它吗?如果有人告诉我如何更新嵌入的文档,那就太好了。

3 回复 | 直到 12 年前

1

15

Nazar Hussain 12 年前

封面以数组形式存储在电影对象中,因此可以执行以下操作:

@movie.covers.clear
@movie.save

或者如果你想有选择性

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

2

1

Nick Ryberg 15 年前

如果您基于名称等属性进行删除,这是可行的,但是如果您已经知道ID并想删除它,请使用以下技巧 p-rob's tubmlr post :

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:(

3

0

Jon Kern 12 年前

这里是一个 quick and dirty complete gist 用于从关联中删除嵌入文档。此处重复:

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