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Functions

This guide covers the Cypher functions available in Grafio for querying and manipulating graph data.

Scalar Functions​

ID​

Returns the internal id of a node or relationship.

MATCH (p:Person {name: 'Alice'})
RETURN ID(p)

With Relationships:

MATCH (a)-[r:KNOWS]->(b)
RETURN ID(r)

labels(node)​

Returns the labels of a node as an array of strings. This corresponds to the node type(s) assigned when the node was created. A node can have multiple labels.

MATCH (p:Person {name: 'Alice'})
RETURN labels(p) AS nodeLabels

Example:

A node created with await graph.addNode('Person', { name: 'Alice' }) will have labels(p) return ['Person'].

type(relationship)​

Returns the relationship type of an edge/relationship as a string.

MATCH (a)-[r:KNOWS]->(b)
RETURN type(r) AS relationshipType

Example:

An edge created with await graph.addEdge(from, to, 'KNOWS') will have type(r) return 'KNOWS'.

Path Functions​

Path functions are used to extract nodes or relationships from a path variable obtained via variable-length matches. When you use a named path in a MATCH clause (e.g., MATCH p = (a)-[:R]->(b)), the path variable contains an alternating sequence:

[node₀, edge₀, node₁, edge₁, ..., nodeₙ]

nodes(path)​

Extracts all nodes from a path. Returns elements at even indices (0, 2, 4, ...).

MATCH p = (start:Person)-[:KNOWS*1..2]->(end:Person)
WHERE start.name = 'Alice'
RETURN nodes(p) AS pathNodes

How it works:

Given a path Alice --[KNOWS]--> Bob --[KNOWS]--> Carol:

  • Path array: [Alice, KNOWS_edge, Bob, KNOWS_edge, Carol]
  • nodes(p) returns: [Alice, Bob, Carol]

relationships(path)​

Extracts all relationships/edges from a path. Returns elements at odd indices (1, 3, 5, ...).

MATCH p = (a:Person)-[:KNOWS*2]->(b:Person)
WHERE a.name = 'Alice'
RETURN relationships(p) AS pathEdges

How it works:

Given a path Alice --[KNOWS]--> Bob --[KNOWS]--> Carol:

  • Path array: [Alice, KNOWS_edge, Bob, KNOWS_edge, Carol]
  • relationships(p) returns: [KNOWS_edge, KNOWS_edge]

Combined Usage​

Often used together to inspect both the nodes and edges of a path:

MATCH p = (a)-[r]->(b)-[r2]->(c)
RETURN nodes(p) AS allNodes, 
       relationships(p) AS allRelationships

Use cases:

  • Debugging path-based queries
  • Analyzing the full structure of traversed paths
  • Extracting node sequences for further processing
  • Building adjacency lists from paths