Graph Pattern Function

In addition to the various relational data-based function operations introduced earlier, NeuG also specifically supports a set of functions for operating on node, edge, and path data generated by graph patterns.

Node Function

Function	Description	Example
ID()	Get the Internal ID of a node/edge	MATCH (a) RETURN ID(a)
LABEL()/LABELS()	Get the label of a node/edge	MATCH (a) RETURN LABEL(a)

Edge Function

In addition to ID and LABEL functions, there are the following edge-based function operations:

Function	Description	Example
START_NODE()	Returns the starting node of edge data	MATCH ()-[b]->() RETURN START_NODE(b);
END_NODE()	Returns the ending node of edge data	MATCH ()-[b]->() RETURN END_NODE(b);

Repeated Path Function

Function	Description	Example
NODES	Returns all nodes from a path	MATCH (a)-[b*2..3]->() RETURN NODES(b);
RELS	Returns all edges from a path	MATCH (a)-[b*2..3]->() RETURN RELS(b);
PROPERTIES	Returns given property from nodes/edges	MATCH (a)-[b*2..3]->() RETURN PROPERTIES(nodes(b), ‘name’), PROPERTIES(rels(b), ‘weight’);
IS_TRAIL	Checks if path contains repeated edges (`true` if no)	MATCH (a)-[b*2..3]->() RETURN IS_TRAIL(b);
IS_ACYCLIC	Checks if path contains repeated nodes (`true` if no)	MATCH (a)-[b*2..3]->() RETURN IS_ACYCLIC(b);
LENGTH	Returns the length of a path	MATCH (a)-[b*2..3]->() RETURN LENGTH(b);