Welcome to Neo4j.rb’s documentation!

Contents:

• Introduction
  • Terminology
    • Neo4j
    • ActiveGraph
  • Code Examples
    • Node
  • Setup
• Setup
  • Ruby on Rails
    • Generating a new app
    • Adding the gem to an existing project
    • Rails configuration
  • Any Ruby Project
    • Driver Instance
  • What if I’m integrating with a pre-existing Neo4j database?
  • Heroku
• Upgrade Guide
  • How to upgrade to activegraph?
    • Transaction API
    • Exceptions
• Rake Tasks
• Node
  • Properties
    • Labels
    • Indexes and Constraints
    • Labels
    • Serialization
    • Enums
  • Scopes
  • Wrapping
  • Callbacks
  • created_at, updated_at
  • Validation
  • id property (primary key)
  • Associations
    • Updating Associations
    • Polymorphic Associations
    • Dependent Associations
    • Association Options
    • Creating Unique Relationships
    • Eager Loading
• Relationship
  • When to Use?
  • Setup
  • Relationship Creation
    • From an Relationship Model
    • From a has_many or has_one association
    • Creating Unique Relationships
  • Query and Loading existing relationships
    • :each_rel, :each_with_rel, or :pluck methods
  • Accessing related nodes
  • Advanced Usage
    • Separation of Relationship Logic
  • Additional methods
  • Regarding: from and to
• Properties
  • Validations
  • Undeclared Properties
    • Types and Conversion
    • Custom Converters
• Unique IDs
  • Defining your own ID
  • Using internal Neo4j IDs as id_property
  • A note regarding constraints
  • Adding IDs to Existing Data
  • Working with Legacy Schemas
• Querying
  • Introduction
  • Node
    • Simple Query Methods
    • Proxy Method Chaining
    • The Query API
    • #proxy_as
    • match_to and first_rel_to
    • Finding in Batches
    • Orm_Adapter
    • Find or Create By…
• Query Examples
  • Example 1: Find all contacts for a user two hops away, but don’t include contacts which are only one hop away
  • Example 2: Simple Recommendation Engine
• QueryClauseMethods
  • ActiveGraph::Core::Query
    • #match
    • #optional_match
    • #using
    • #where
    • #where_not
    • #match_nodes
    • #unwind
    • #return
    • #order
    • #limit
    • #skip
    • #with
  • #with_distinct
    • #create
    • #create_unique
    • #merge
    • #delete
    • #set_props
    • #set
    • #on_create_set
    • #on_match_set
    • #remove
    • #start
    • clause combinations
• Configuration
  • In Rails
  • Other Ruby apps
  • Variables
  • Instrumented events
• Migrations
  • Generators
  • Transactions
  • The schema file
  • Tasks
    • neo4j:migrate:all
    • neo4j:migrate
    • neo4j:migrate:up
    • neo4j:migrate:down
    • neo4j:migrate:status
    • neo4j:rollback
    • neo4j:schema:dump
    • neo4j:schema:load
  • Integrate Neo4j.rb with ActiveRecord migrations
  • Migration Helpers
    • #execute
    • #query
    • #remove_property
    • #rename_property
    • #drop_nodes
    • #add_label
    • #add_labels
    • #remove_label
    • #remove_labels
    • #rename_label
    • #add_constraint
    • #drop_constraint
    • #add_index
    • #drop_index
    • #say
    • #say_with_time
    • #populate_id_property
    • #relabel_relation
    • #change_relations_style
• Testing
  • How to clear the database
    • Cypher DELETE
    • The database_cleaner gem
    • Delete data files
    • RSpec Transaction Rollback
    • Using Rack::Test
• Contributing
  • The Neo4j.rb Project
  • Low Hanging Fruit
  • Communicating With the Neo4j.rb Team
  • Running Specs
  • Before you submit your pull request
    • Automated Tools
    • Documentation
• Additional Resources
• Helper Gems
  • devise-activegraph
  • cancancan-activegraph
  • neo4j-paperclip
  • neo4jrb_spatial
  • neo4j-rspec

ActiveGraph (the activegraph gem) is a Ruby Object-Graph-Mapper (OGM) for the Neo4j graph database. It tries to follow API conventions established by ActiveRecord and familiar to most Ruby developers but with a Neo4j flavor.

Ruby

(software) A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write.

Graph Database

(computer science) A graph database stores data in a graph, the most generic of data structures, capable of elegantly representing any kind of data in a highly accessible way.

Neo4j

(databases) The world’s leading graph database

If you’re already familiar with ActiveRecord, DataMapper, or Mongoid, you’ll find the Object Model features you’ve come to expect from an O*M:

• Properties
• Indexes / Constraints
• Callbacks
• Validation
• Associations

Because relationships are first-class citizens in Neo4j, models can be created for both nodes and relationships.

Additional features include

• A chainable arel-inspired query builder
• Transactions
• Migration framework

Requirements

• Ruby 2.5 + (tested in MRI and JRuby)
• Neo4j 3.4 +

Indices and tables

• Index
• Module Index
• Search Page