Element Functions

Example Graph

GQL
INSERT (p1:Paper {_id:'P1', title:'Efficient Graph Search', score:6, author:'Alex'}),
       (p2:Paper {_id:'P2', title:'Optimizing Queries', score:9, author:'Alex'}),
       (p3:Paper {_id:'P3', title:'Path Patterns', score:7, author:'Zack'}),
       (p1)-[:Cites {weight:2}]->(p2),
       (p2)-[:Cites {weight:1}]->(p3)

id()

Gets the unique identifier _id of a graph element. element_id() is a synonym.

NOTE

On an edge _id disabled graph (see Node and Edge IDs) edges have no user-visible _id, so id(e) raises an error.

GQL
MATCH (n)-[e]->()
RETURN id(n), id(e)

Result:

internal_id()

Returns the system-internal numeric identifier (the _uuid) of a node or edge as a decimal string.

NOTE

Unlike id() which can error on edges in an edge _id disabled graph, internal_id() always resolves. It's the function form of the built-in _uuid property and works on both edge _id enabled and disabled graphs.

GQL
MATCH (n)-[e]->()
RETURN internal_id(n), internal_id(e)

Result:

Equivalent property-form access:

GQL
MATCH (n)-[e]->()
RETURN n._uuid, e._uuid

labels()

Gets the labels of a graph element.

GQL
MATCH (n)-[e]->()
RETURN labels(n), labels(e)

Result:

type()

Gets the label of an edge. Equivalent to labels() for edges.

GQL
MATCH ()-[e]->()
RETURN type(e)

Result:

keys()

Returns the property names of a node, edge, or key names of a record.

GQL
MATCH (n:Paper)
RETURN keys(n)

Result:

GQL
LET myRecord = {x: 1, y: 3, z: 34}
RETURN keys(myRecord)

Result:

values()

Returns the property values of a node, edge, or values of a record.

GQL
LET myRecord = {x: 1, y: 3, z: 34}
RETURN values(myRecord)

Result:

properties()

Returns the properties of a node or edge as a record.

GQL
MATCH (n:Paper)
RETURN properties(n)

Result:

property_exists()

Checks whether a property exists on a node or edge.

GQL
MATCH (n:Paper)
RETURN n._id, property_exists(n, "score"), property_exists(n, "rating")

Result: