```
public interface Pg
```
A mapping between Hydra's property-graph model (hydra.pg.model, TinkerPop-shaped) and the Neo4j model (hydra.neo4j.model). It is not an isomorphism and not invertible: ids and values are bridged by caller-supplied conversions (Neo4jMapping); a Neo4j relationship type expands into a property-graph edge label conditionally on the schema; and multi-label nodes, which Hydra's single-label vertices cannot represent, are rejected.

Method Summary

Static Methods
Modifier and Type	Method	Description
`static EdgeLabel`	`edgeLabelForRelationship(GraphType gt, NodeLabel startLabel, NodeLabel endLabel, RelationshipType relType)`	Compute the property-graph edge label for a Neo4j relationship type, given the schema and endpoint labels.
`static <T0> Either<java.lang.String,Relationship>`	`edgeToRelationship(Neo4jMapping<T0> mapping, Edge<T0> edge)`	Convert a property-graph edge to a Neo4j relationship (edge label -> UPPER_SNAKE type).
`static <T0> Either<java.lang.String,Pair<java.util.List<Node>,java.util.List<Relationship>>>`	`graphToNeo4j(Neo4jMapping<T0> mapping, Graph<T0> graph)`	Convert a whole property-graph Graph to a Neo4j graph (nodes and relationships).
`static <T0> Either<java.lang.String,Pair<java.util.List<Vertex<T0>>,java.util.List<Edge<T0>>>>`	`neo4jToGraph(Neo4jMapping<T0> mapping, GraphType gt, java.util.List<Node> nodes, java.util.List<Relationship> rels)`	Convert a Neo4j graph (nodes and relationships) to property-graph vertices and edges against a GraphType.
`static <T0> Either<java.lang.String,Vertex<T0>>`	`nodeToVertex(Neo4jMapping<T0> mapping, Node node)`	Convert a Neo4j node to a property-graph vertex; fails on a multi-label node.
`static <T0> Either<java.lang.String,Edge<T0>>`	`relationshipToEdge(Neo4jMapping<T0> mapping, GraphType gt, NodeLabel startLabel, NodeLabel endLabel, Relationship rel)`	Convert a Neo4j relationship to a property-graph edge, expanding the type via the schema and endpoint labels.
`static <T0> Either<java.lang.String,Node>`	`vertexToNode(Neo4jMapping<T0> mapping, Vertex<T0> vertex)`	Convert a property-graph vertex to a Neo4j node (single label -> singleton label set).

Method Detail

edgeLabelForRelationship

static EdgeLabel edgeLabelForRelationship(GraphType gt,
                                          NodeLabel startLabel,
                                          NodeLabel endLabel,
                                          RelationshipType relType)

Compute the property-graph edge label for a Neo4j relationship type, given the schema and endpoint labels.

edgeToRelationship

static <T0> Either<java.lang.String,Relationship> edgeToRelationship(Neo4jMapping<T0> mapping,
                                                                           Edge<T0> edge)

Convert a property-graph edge to a Neo4j relationship (edge label -> UPPER_SNAKE type).

graphToNeo4j

static <T0> Either<java.lang.String,Pair<java.util.List<Node>,java.util.List<Relationship>>> graphToNeo4j(Neo4jMapping<T0> mapping,
                                                                                                                      Graph<T0> graph)

Convert a whole property-graph Graph to a Neo4j graph (nodes and relationships).

neo4jToGraph

static <T0> Either<java.lang.String,Pair<java.util.List<Vertex<T0>>,java.util.List<Edge<T0>>>> neo4jToGraph(Neo4jMapping<T0> mapping,
                                                                                                                        GraphType gt,
                                                                                                                        java.util.List<Node> nodes,
                                                                                                                        java.util.List<Relationship> rels)

Convert a Neo4j graph (nodes and relationships) to property-graph vertices and edges against a GraphType.

nodeToVertex

static <T0> Either<java.lang.String,Vertex<T0>> nodeToVertex(Neo4jMapping<T0> mapping,
                                                                   Node node)

Convert a Neo4j node to a property-graph vertex; fails on a multi-label node.

relationshipToEdge

static <T0> Either<java.lang.String,Edge<T0>> relationshipToEdge(Neo4jMapping<T0> mapping,
                                                                       GraphType gt,
                                                                       NodeLabel startLabel,
                                                                       NodeLabel endLabel,
                                                                       Relationship rel)

Convert a Neo4j relationship to a property-graph edge, expanding the type via the schema and endpoint labels.

vertexToNode

static <T0> Either<java.lang.String,Node> vertexToNode(Neo4jMapping<T0> mapping,
                                                             Vertex<T0> vertex)

Convert a property-graph vertex to a Neo4j node (single label -> singleton label set).

Interface Pg