我正在尝试创建博客，并将评论与帖子相关联。
我定义关系的方式如下：
#post.rb
has_many :in, :comments, origin: :post # 5.03 try sth else
#comment.rb
has_one :out, :post, type: :comments_on
我得到的错误如下。
Neo4j::ActiveNode::HasN::NonPersistedNodeError in CommentsController#create
Unable to create relationship with non-persisted nodes
应用程序跟踪：
app/controllers/comments_controller.rb:27:in `new'
app/controllers/comments_controller.rb:27:in `create'
框架追踪：
neo4j (5.0.2) lib/neo4j/active_node/has_n.rb:185:in `validate_persisted_for_association!'
neo4j (5.0.2) lib/neo4j/active_node/has_n.rb:350:in `block in define_has_one_setter'
neo4j (5.0.2) lib/neo4j/shared/property.rb:55:in `block in send_props'
neo4j (5.0.2) lib/neo4j/shared/property.rb:55:in `each'
neo4j (5.0.2) lib/neo4j/shared/property.rb:55:in `send_props'
neo4j (5.0.2) lib/neo4j/shared/property.rb:25:in `initialize'
neo4j (5.0.2) lib/neo4j/active_node/property.rb:7:in `initialize'
actionpack (4.2.3) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.3) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.3) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.3) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.3) lib/active_support/callbacks.rb:115:in `call'
activesupport (4.2.3) lib/active_support/callbacks.rb:115:in `call'
activesupport (4.2.3) lib/active_support/callbacks.rb:553:in `block (2 levels) in compile'
activesupport (4.2.3) lib/active_support/callbacks.rb:503:in `call'
activesupport (4.2.3) lib/active_support/callbacks.rb:503:in `call'
activesupport (4.2.3) lib/active_support/callbacks.rb:88:in `run_callbacks'
actionpack (4.2.3) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.3) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.3) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (4.2.3) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.3) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.3) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.3) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.3) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
actionpack (4.2.3) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.3) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.3) lib/action_controller/metal.rb:196:in `dispatch'
actionpack (4.2.3) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.3) lib/action_controller/metal.rb:237:in `block in action'
actionpack (4.2.3) lib/action_dispatch/routing/route_set.rb:76:in `call'
actionpack (4.2.3) lib/action_dispatch/routing/route_set.rb:76:in `dispatch'
actionpack (4.2.3) lib/action_dispatch/routing/route_set.rb:45:in `serve'
actionpack (4.2.3) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.3) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.3) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.3) lib/action_dispatch/routing/route_set.rb:821:in `call'
rack (1.6.4) lib/rack/etag.rb:24:in `call'
rack (1.6.4) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.4) lib/rack/head.rb:13:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/cookies.rb:560:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.3) lib/active_support/callbacks.rb:84:in `run_callbacks'
actionpack (4.2.3) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
web-console (2.2.1) lib/web_console/middleware.rb:39:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.3) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.3) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.3) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.3) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.3) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.3) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.4) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.3) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
actionpack (4.2.3) lib/action_dispatch/middleware/static.rb:116:in `call'
rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
railties (4.2.3) lib/rails/engine.rb:518:in `call'
railties (4.2.3) lib/rails/application.rb:165:in `call'
rack (1.6.4) lib/rack/lock.rb:17:in `call'
rack (1.6.4) lib/rack/content_length.rb:15:in `call'
rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
/usr/local/Cellar/ruby/2.2.2/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/usr/local/Cellar/ruby/2.2.2/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/usr/local/Cellar/ruby/2.2.2/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'
请求： 参数：
{"utf8"=>"✓",
"authenticity_token"=>"nbc5AbgDSLmbt0Rh2FjYfQxuq8/N8jbNtfwPr28cSC+VUjK9YHZYWqx5e5LyZe7uNU8f2msFisLwaT+pgLDn3w==",
"comment"=>{"body"=>"comment body",
"post"=>"b4a6dd87-cb67-46fb-b26a-147065fce038"},
"commit"=>"Create Comment"}
我正在关注使用Neo4jrb gem和rails创建博客的介绍性视频。 Neo4j ruby gem intro screencast
我在github上发现了类似的问题，但我不确定这是否也是同样的问题。
问题似乎在于创建关系，我没有正确定义关系，有什么建议吗？
谢谢！
答案 0 :(得分：0)
在Neo4j::Config[:autosave_on_assignment] = true中设置applicaton.rb解决了问题。
您可以在Github上看到完整的问题解答。