ActiveRecord似乎並不理解,給定一組具有嵌套屬性的現有記錄的參數,它可以創建一個新的嵌套記錄,該記錄本身具有嵌套的現有記錄。 (關係樹:Existing -> New -> Existing
)AcitveRecord不會爲具有嵌套現有記錄的新關聯記錄accept_nested_attributes_
這是一個錯誤,還是我錯過了什麼?
讓我給你看一個簡單的例子。
這裏是我的模型:
class User < ActiveRecord::Base
has_many :posts
attr_accessible :name, :posts_attributes
accepts_nested_attributes_for :posts
end
class Post < ActiveRecord::Base
belongs_to :group
belongs_to :user
attr_accessible :content, :title, :group_attributes
accepts_nested_attributes_for :group
end
class Group < ActiveRecord::Base
has_many :posts
attr_accessible :name
end
我做了每個表中的一個記錄,因此它們有關的,所以每個表都有一個記錄在其與id=1
- 這是已知的。現在,如果我有一個現有的用戶,新郵,和現有的組,並嘗試更新使用accepts_nested_attributes_for
該記錄,它不喜歡它:
1.9.3-p125 :044 > params
{
:id => 1,
:name => "Billy",
:posts_attributes => [
[0] {
:title => "Title",
:content => "Some magnificent content for you!",
:group_attributes => {
:id => 1,
:name => "Group 1"
}
}
]
}
1.9.3-p125 :045 > u
#<User:0x00000002f7f380> {
:id => 1,
:name => "Billy",
:created_at => Fri, 03 Aug 2012 20:21:37 UTC +00:00,
:updated_at => Fri, 03 Aug 2012 20:21:37 UTC +00:00
}
1.9.3-p125 :046 > u.update_attributes params
(0.1ms) begin transaction
(0.1ms) rollback transaction
ActiveRecord::RecordNotFound: Couldn't find Group with ID=1 for Post with ID=
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:462:in `raise_nested_attributes_record_not_found'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:332:in `assign_nested_attributes_for_one_to_one_association'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:288:in `group_attributes='
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:94:in `block in assign_attributes'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:93:in `each'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:93:in `assign_attributes'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/base.rb:498:in `initialize'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/reflection.rb:183:in `new'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/reflection.rb:183:in `build_association'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/associations/association.rb:233:in `build_record'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/associations/collection_association.rb:112:in `build'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:405:in `block in assign_nested_attributes_for_collection_association'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:400:in `each'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:400:in `assign_nested_attributes_for_collection_association'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/nested_attributes.rb:288:in `posts_attributes='
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:85:in `block in assign_attributes'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:78:in `each'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/attribute_assignment.rb:78:in `assign_attributes'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/persistence.rb:216:in `block in update_attributes'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/transactions.rb:295:in `block in with_transaction_returning_status'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/transactions.rb:208:in `transaction'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/transactions.rb:293:in `with_transaction_returning_status'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/activerecord-3.2.7/lib/active_record/persistence.rb:215:in `update_attributes'
from (irb):15
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.7/lib/rails/commands/console.rb:47:in `start'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.7/lib/rails/commands/console.rb:8:in `start'
from /home/trevor/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.7/lib/rails/commands.rb:41:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'1.9.3-p125 :047 >
它認爲它不能找到一組(有一個已知的ID),與一個新的Post相關。 它可以在我從group_attributes
中刪除ID時生效(但會創建一個新的組記錄)。 當我給posts_attributes
一個ID時,它會起作用,並從group_attributes
中刪除該ID(並再次創建一個新組)。 它也適用於全部都有ID的情況。
的關係工作:
1.9.3-p125 :059 > p = Post.new({ group_attributes: { name: 'Testing' } })
#<Post:0x00000004212380> {
:id => nil,
:title => nil,
:content => nil,
:group_id => nil,
:user_id => nil,
:created_at => nil,
:updated_at => nil
}
1.9.3-p125 :060 > p.group
[
[0] #<Group:0x00000004211868> {
:id => nil,
:name => "Testing",
:created_at => nil,
:updated_at => nil
}
]
User
創建過程中使用posts_attributes
和group_attributes
時,如果所有的記錄都新也完全適用。
不應該在第一個例子中工作嗎? ActiveRecord應該足夠聰明以解決這個問題......!
您在用戶模型中缺少'has_many:comments'。 – jordanpg 2012-08-03 21:07:52
哎呀,這個問題依然存在。 :)我會簡化這個例子。 – wulftone 2012-08-03 21:17:28
長問題,但新記錄如何具有現有的關聯? – pjammer 2012-08-03 21:25:49