Rails：如果一个交易失败，则回滚所有交易

Question

So I have this configurations

class Post < ActiveRecord::Base
has_many :photo_albums

class PhotoAlbum < ActiveRecord::Base
has_many :photos

and I want to do the following

@post = Post.new(post_params)
@photo_album = @post.photo_albums.create(name: 'album name')
@photo_urls = params[:photo_urls]
@photo_urls.each do |pu|
 @photo_album.photos.create(url: pu)
end
@post.save

Now what I want is that, if @post.save fails then all transactions of photo_albums, photos should rollback.

Answer 1

you can just add an if filter if @post.save and write the code block to create photo_album and photos only if the @post is saved

@post = Post.new(post_params)
if @post.save
  @photo_album = @post.photo_albums.create(name: 'album name')
  @photo_urls = params[:photo_urls]
  @photo_urls.each do |pu|
   @photo_album.photos.create(url: pu)
  end 
else
  # handle @post.save fail
end

Answer 2

Look into using ActiveRecord::Base.transaction .

See this literature .

Answer 3

Simple.

ActiveRecord::Base.transaction do
  @post = Post.new(post_params)
  @photo_album = @post.photo_albums.create(name: 'album name')
  @photo_urls = params[:photo_urls]
  @photo_urls.each do |pu|
    @photo_album.photos.create(url: pu)
  end
  @post.save
end