Neo4j inconsistent behaviour of model classes

问题

I have created 5 models in my project using ActiveNode model and using neo4j gem.

There is a model named Disease, defined as:

  class Disease
    include Neo4j::ActiveNode
    property :disease, type: String, constraint: :unique
    property :created_at, type: DateTime
    property :updated_at, type: DateTime

    enum factor_effect: [:relief, :worsen]

    # Associations
    has_many :in, :factors, type: :AFFECTED_BY
  end

and Factor:

  class Factor
    include Neo4j::ActiveNode
    property :factor, type: String, constraint: :unique
  end

I am able to create nodes for Factor easily but for Disease, it gives error with create function and returns a QueryProxy object with new method. (As for other models, they are also working just as Factor, properly as expected)

Here are few commands run on console:

2.3.3 :012 >   f = Factor.new
=> #<Factor uuid: nil, factor: nil>
2.3.3 :013 > f.factor = "drinking more water"
=> "drinking more water"
2.3.3 :014 > f
=> #<Factor uuid: nil, factor: "drinking more water">
2.3.3 :015 > f.save
HTTP REQUEST: 49ms GET http://localhost:7474/db/data/schema/constraint (0 bytes)
HTTP REQUEST: 8ms GET http://localhost:7474/db/data/schema/index (0 bytes)
WARNING: The constraint option is no longer supported (Defined on Disease for disease)
WARNING: The constraint option is no longer supported (Defined on Factor for factor)
CYPHER CREATE (n:`Factor`) SET n = {props} RETURN n | {:props=>{:uuid=>"33f683d4-a6b2-4c7a-84f9-549088780033", :factor=>"drinking more water"}}
HTTP REQUEST: 682ms POST http://localhost:7474/db/data/transaction (1 bytes)
HTTP REQUEST: 385ms POST http://localhost:7474/db/data/transaction/5/commit (0 bytes)
WARNING: The constraint option is no longer supported (Defined on Disease for disease)
WARNING: The constraint option is no longer supported (Defined on Factor for factor)
=> true
2.3.3 :016 > f
=> #<Factor uuid: "33f683d4-a6b2-4c7a-84f9-549088780033", factor: "drinking more water">

So Factor node is created easily. Although there are couple of warnings and I'd like to know the reason for that.

When I do the same for Disease:

2.3.3 :020 >   d = Disease.new
WARNING: The constraint option is no longer supported (Defined on Disease for disease)
WARNING: The constraint option is no longer supported (Defined on Factor for factor)
CYPHER
MATCH (result_disease:`Disease`)
RETURN result_disease
HTTP REQUEST: 82ms POST http://localhost:7474/db/data/transaction/commit (1 bytes)
=> #<QueryProxy  []> 
2.3.3 :021 > Disease.all
WARNING: The constraint option is no longer supported (Defined on Disease for disease)
WARNING: The constraint option is no longer supported (Defined on Factor for factor)
    Disease
    MATCH (n:`Disease`)
    RETURN n
    HTTP REQUEST: 11ms POST http://localhost:7474/db/data/transaction/commit (1 bytes)
    => #<QueryProxy Disease []>

Its getting really bad for me and I'm not getting any workaround for this. Please help!!

回答1:

I'm really not sure why you are getting a QueryProxy for Disease.new. I've tried testing your code locally and I get:

#<Disease uuid: nil, created_at: nil, disease: nil, factor_effect: nil, updated_at: nil>

Maybe there is something else in your code that is affecting things? You might try removing code until it starts working (though that's just a stab in the dark)

The WARNINGs are because constraint: :unique is no longer supported on properties. That option used to create constraints automatically when the model was loaded, but it became a nightmare to maintain. Constraints should now be created with migrations. See the migration guide, especially this section

来源：https://stackoverflow.com/questions/44930760/neo4j-inconsistent-behaviour-of-model-classes

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ruby-on-rails

neo4j

neo4j.rb