neo4j RuntimeError：未定义会话

Question

class Client
=begin
  Clients are individual users
=end
  include Neo4j::ActiveNode
  include Neo4j::UndeclaredProperties
  include Neo4j::Timestamps # will give model created_at and updated_at timestamps 

  property :bot_client_id
  property :sms
  property :telegram_id
  property :first_name
  property :last_name
  property :email

end

当我创建一个新节点时，没有填充 uuid：

client = Client.new

当我尝试查找已创建的客户端时，出现运行时错误：

client = Client.find_by(bot_client_id: 'botid')

错误详情：

RuntimeError: No session defined!
    from /usr/local/rvm/gems/ruby-2.2.1/gems/neo4j-8.0.13/lib/neo4j/active_base.rb:9:in `block in current_session'
    from /usr/local/rvm/gems/ruby-2.2.1/gems/neo4j-8.0.13/lib/neo4j/active_base.rb:8:in `tap'
    from /usr/local/rvm/gems/ruby-2.2.1/gems/neo4j-8.0.13/lib/neo4j/active_base.rb:8:in `current_session'
    from /usr/local/rvm/gems/ruby-2.2.1/gems/neo4j-8.0.13/lib/neo4j/model_schema.rb:35:in `model_constraints'
    from /usr/local/rvm/gems/ruby-2.2.1/gems/neo4j-8.0.13/lib/neo4j/model_schema.rb:131:in `each_schema_element'

我有一个def initialize 方法，其中包括：

neo4j_adaptor = Neo4j::Core::CypherSession::Adaptors::HTTP.new('http://user:pass@host:7474')
Neo4j::ActiveBase.on_establish_session { Neo4j::Core::CypherSession.new(neo4j_adaptor) }

Answer 1

您建立会话的代码是正确的，尽管我不知道您的意思是它在def initialize 中。那是在类的initialize 方法中吗？如果是这样，该类是否正在初始化（可能放一个puts 在那里查看）？我建议将设置代码放在您的应用程序的某个部分，所有内容都在全局设置。

我想我回答了uuid 未被填充here 的问题，当然，在对象被持久化（通过create 或save）之前，您将无法使用find_by。