Basics

Each type in your GraphQL type definitions can be mapped to an entity in your Neo4j database, such as nodes, relationships, and relationship properties. This page describes how that can be done.

Nodes

The most basic mapping, it uses GraphQL type names to map to the Neo4j node label. For example, to represent a node with label "Movie" and a single property "title" of type string:

type Movie {
    title: String
}

Relationships

Relationships are represented by marking particular fields with a directive — in this case, @relationship. It defines the relationship type in the database, as well as which direction that relationship goes in.

To add a second node type, "Actor", and connect the two together, you should do the following:

type Movie {
    title: String
    actors: [Actor!]! @relationship(type: "ACTED_IN", direction: IN)
}

type Actor {
    name: String
    movies: [Movie!]! @relationship(type: "ACTED_IN", direction: OUT)
}

Note that, in this case, there is a directive on each "end" of the relationship, but it is not essential.

Relationship properties

In order to add properties to a relationship, you need to add a new type to your type definitions. This time, however, it should be an interface which must be decorated with the @relationshipProperties directive.

For example, for the "ACTED_IN" relationship, add a property "roles":

type Movie {
    title: String
    actors: [Actor!]! @relationship(type: "ACTED_IN", direction: IN, properties: "ActedIn")
}

type Actor {
    name: String
    movies: [Movie!]! @relationship(type: "ACTED_IN", direction: OUT, properties: "ActedIn")
}

interface ActedIn @relationshipProperties {
    roles: [String]
}

Note that in addition to this interface type, there is an added a key properties in the existing @relationship directives. For more information, see Type definitions → Relationships.