List Functions

Data Setup

SELECT * from cypher('graph_name', $$
CREATE (A:Person {name: 'Alice', age: 38, eyes: 'brown'}),
	(B:Person {name: 'Bob', age: 25, eyes: 'blue'}),
	(C:Person {name: 'Charlie', age: 53, eyes: 'green'}),
	(D:Person {name: 'Daniel', age: 54, eyes: 'brown'}),
	(E:Person {name: 'Eskil', age: 41, eyes: 'blue', array: ['one', 'two', 'three']}),
	(A)-[:KNOWS]->(B),
	(A)-[:KNOWS]->(C),
	(B)-[:KNOWS]->(D),
	(C)-[:KNOWS]->(D),
	(B)-[:KNOWS]->(E)
$$) as (result agtype);

keys

keys returns a list containing the string representations for all the property names of a vertex, edge, or map.

Syntax:keys(expression)

Returns:

An Agtype list containing string agtype elements

Arguments:

Name	Description
path	An expression that returns a vertex, edge, or map.

Considerations:

keys(null) returns null.

Query:

SELECT * from cypher('graph_name', $$
	MATCH (a)
	WHERE a.name = 'Alice'
	RETURN keys(a)
$$) as (result agtype);

A list containing the names of all the properties on the vertex bound to a is returned.

Result:

keys

["age", "eyes", "name"]

1 rows

range

range() returns a list comprising all integer values within a range bounded by a start value start and end value end, where the difference step between any two consecutive values is constant; i.e. an arithmetic progression. The range is inclusive, and the arithmetic progression will therefore always contain start and—depending on the values of start, step and end—end.

Syntax:range(start, end [, step])

Returns:

An Agtype list containing edge entities

Arguments:

Name	Description
start	An expression that returns an integer value.
end	An expression that returns an integer value.
step	A numeric expression defining the differencebetween any two consecutive values, with adefault of 1.

Query:

SELECT *
FROM cypher('graph_name', $$
	RETURN range(0, 10), range(2, 18, 3)
$$) as (no_step agtype, step agtype);

Two lists of numbers in the given ranges are returned.

Result:

no_step	step
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]	[2, 5, 8, 11, 14, 17]
1 row

labels

labels returns a list containing the string representations for all the labels of a node.

Syntax:labels(vertex)

Returns:

An Agtype list containing String elements

Arguments:

Name	Description
vertex	An expression that returns a single vertex.

Considerations:

labels(null) returns null.

Query:

SELECT *
FROM cypher('graph_name', $$
	MATCH (a)
	WHERE a.name = 'Alice'
	RETURN labels(a)
$$) as (edges agtype);

A list containing all the labels of the node bound to a is returned.

Result:

edges
["Person"]
1 row

relationships

relationships() returns a list containing all the relationships in a path.

Syntax:relationships(path)

Returns:

An Agtype list containing edge entities

Arguments:

Name	Description
path	An expression that returns an Agtype path.

Considerations:

relationships(null) returns null.

Query:

SELECT *
FROM cypher('graph_name', $$
	MATCH p = (a)-[]->(b)-[]->(c)
	WHERE a.name = 'Alice' AND c.name = 'Eskil'
	RETURN relationships(p)
$$) as (edges agtype);

A list containing all the edges in the path p is returned.

Result:

edges
[{"id": 1125899906842640, "label": "KNOWS", "end_id": 844424930131989, "start_id": 844424930131988, "properties": {}}::edge, {"id": 1125899906842644, "label": "KNOWS", "end_id": 844424930131992, "start_id": 844424930131989, "properties": {}}::edge]
1 row