How to get value of field from Neo4j database by neo4j.rb in Rails?

Question

Which method has neo4j.rb to get value of <id> field from Neo4j database?

Answer 1

It depends what you mean ;)

The Neo4j.rb project has two main gems: neo4j and neo4j-core. If you're using the neo4j gem to create ActiveNode / ActiveRel objects in Neo4j, you can either use the node_object.id / node_object.uuid methods to get the UUID generated by the gem or the node_object.neo_id method to get the Neo ID generated by the database. The gem generates UUIDs because Neo4j internal IDs can be recycled and so don't offer the best option for external references to nodes. Keep in mind, though, that if you use the id_property method in a model this will change the behavior of IDs generated by the gem.

The neo4j-core gem allows you to make Cypher queries directly and from there you can get whatever you want. An example:

# Gets the Neo4j internal ID
Neo4j::Session.current.query("MATCH (n) WHERE n.name = 'Sue' RETURN ID(n)")