GQL functions

Preview

This product or feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA products and features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

Note: To provide feedback or request support for this feature, send an email to [e-mail].

GoogleSQL for BigQuery supports the following GQL functions:

Function list

Name	Summary
DESTINATION_NODE_ID	Gets a unique identifier of a graph edge's destination node.
EDGES	Gets the edges in a graph path. The resulting array retains the original order in the graph path.
ELEMENT_ID	Gets a graph element's unique identifier.
LABELS	Gets the labels associated with a graph element.
NODES	Gets the nodes in a graph path. The resulting array retains the original order in the graph path.
PATH_FIRST	Gets the first node in a graph path.
PATH_LAST	Gets the last node in a graph path.
PATH_LENGTH	Gets the number of edges in a graph path.
SOURCE_NODE_ID	Gets a unique identifier of a graph edge's source node.

DESTINATION_NODE_ID

DESTINATION_NODE_ID(edge_element)

Description

Gets a unique identifier of a graph edge's destination node. The unique identifier is only valid for the scope of the query where it's obtained.

Definitions

• edge_element: A GRAPH_ELEMENT value that represents an edge.

Details

Returns NULL if edge_element is NULL.

Return type

STRING

Examples

GRAPH graph_db.FinGraph
MATCH (:Person)-[o:Owns]->(a:Account)
RETURN a.id AS account_id, DESTINATION_NODE_ID(o) AS destination_node_id

/*------------------------------------------+
 |account_id | destination_node_id          |
 +-----------|------------------------------+
 | 7         | mUZpbkdyYXBoLkFjY291bnQAeJEO |
 | 16        | mUZpbkdyYXBoLkFjY291bnQAeJEg |
 | 20        | mUZpbkdyYXBoLkFjY291bnQAeJEo |
 +------------------------------------------*/

Note that the actual identifiers obtained may be different from what's shown above.

EDGES

EDGES(graph_path)

Description

Gets the edges in a graph path. The resulting array retains the original order in the graph path.

Definitions

• graph_path: A GRAPH_PATH value that represents a graph path.

Details

If graph_path is NULL, returns NULL.

Return type

ARRAY<GRAPH_ELEMENT>

Examples

GRAPH graph_db.FinGraph
MATCH p=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LET es = EDGES(p)
RETURN TO_JSON(es) AS edges

ELEMENT_ID

ELEMENT_ID(element)

Description

Gets a graph element's unique identifier. The unique identifier is only valid for the scope of the query where it's obtained.

Definitions

• element: A GRAPH_ELEMENT value.

Details

Returns NULL if element is NULL.

Return type

STRING

Examples

GRAPH graph_db.FinGraph
MATCH (p:Person)-[o:Owns]->(:Account)
RETURN p.name AS name, ELEMENT_ID(p) AS node_element_id, ELEMENT_ID(o) AS edge_element_id

/*--------------------------------------------------------------------------------------------------------------------------------------------+
 | name | node_element_id              | edge_element_id                                                                                      |
 +------|------------------------------|------------------------------------------------------------------------------------------------------+
 | Alex | mUZpbkdyYXBoLlBlcnNvbgB4kQI= | mUZpbkdyYXBoLlBlcnNvbk93bkFjY291bnQAeJECkQ6ZRmluR3JhcGguUGVyc29uAHiRAplGaW5HcmFwaC5BY2NvdW50AHiRDg== |
 | Dana | mUZpbkdyYXBoLlBlcnNvbgB4kQQ= | mUZpbkdyYXBoLlBlcnNvbk93bkFjY291bnQAeJEGkSCZRmluR3JhcGguUGVyc29uAHiRBplGaW5HcmFwaC5BY2NvdW50AHiRIA== |
 | Lee  | mUZpbkdyYXBoLlBlcnNvbgB4kQY= | mUZpbkdyYXBoLlBlcnNvbk93bkFjY291bnQAeJEEkSiZRmluR3JhcGguUGVyc29uAHiRBJlGaW5HcmFwaC5BY2NvdW50AHiRKA== |
 +--------------------------------------------------------------------------------------------------------------------------------------------*/

Note that the actual identifiers obtained may be different from what's shown above.

LABELS

LABELS(element)

Description

Gets the labels associated with a graph element and preserves the original case of each label.

Definitions

• element: A GRAPH_ELEMENT value that represents the graph element to extract labels from.

Details

Returns NULL if element is NULL.

Return type

ARRAY<STRING>

Examples

GRAPH graph_db.FinGraph
MATCH (n:Person|Account)
RETURN LABELS(n) AS label, n.id

/*----------------+
 | label     | id |
 +----------------+
 | [Account] | 7  |
 | [Account] | 16 |
 | [Account] | 20 |
 | [Person]  | 1  |
 | [Person]  | 2  |
 | [Person]  | 3  |
 +----------------*/

NODES

NODES(graph_path)

Description

Gets the nodes in a graph path. The resulting array retains the original order in the graph path.

Definitions

• graph_path: A GRAPH_PATH value that represents a graph path.

Details

Returns NULL if graph_path is NULL.

Return type

ARRAY<GRAPH_ELEMENT>

Examples

GRAPH graph_db.FinGraph
MATCH p=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LET ns = NODES(p)
RETURN
  JSON_QUERY(TO_JSON(ns)[0], '$.labels') AS labels,
  JSON_QUERY(TO_JSON(ns)[0], '$.properties.nick_name') AS nick_name;

/*--------------------------------+
 | labels      | nick_name        |
 +--------------------------------+
 | ["Account"] | "Vacation Fund"  |
 | ["Account"] | "Rainy Day Fund" |
 | ["Account"] | "Rainy Day Fund" |
 | ["Account"] | "Rainy Day Fund" |
 | ["Account"] | "Vacation Fund"  |
 | ["Account"] | "Vacation Fund"  |
 | ["Account"] | "Vacation Fund"  |
 | ["Account"] | "Rainy Day Fund" |
 +--------------------------------*/

PATH_FIRST

PATH_FIRST(graph_path)

Description

Gets the first node in a graph path.

Definitions

• graph_path: A GRAPH_PATH value that represents the graph path to extract the first node from.

Details

Returns NULL if graph_path is NULL.

Return type

GRAPH_ELEMENT

Examples

GRAPH graph_db.FinGraph
MATCH p=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LET f = PATH_FIRST(p)
RETURN
  LABELS(f) AS labels,
  f.nick_name AS nick_name;

/*--------------------------+
 | labels  | nick_name      |
 +--------------------------+
 | Account | Vacation Fund  |
 | Account | Rainy Day Fund |
 | Account | Rainy Day Fund |
 | Account | Vacation Fund  |
 | Account | Vacation Fund  |
 | Account | Vacation Fund  |
 | Account | Rainy Day Fund |
 +--------------------------*/

PATH_LAST

PATH_LAST(graph_path)

Description

Gets the last node in a graph path.

Definitions

• graph_path: A GRAPH_PATH value that represents the graph path to extract the last node from.

Details

Returns NULL if graph_path is NULL.

Return type

GRAPH_ELEMENT

Examples

GRAPH graph_db.FinGraph
MATCH p=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LET f = PATH_LAST(p)
RETURN
  LABELS(f) AS labels,
  f.nick_name AS nick_name;

/*--------------------------+
 | labels  | nick_name      |
 +--------------------------+
 | Account | Vacation Fund  |
 | Account | Vacation Fund  |
 | Account | Vacation Fund  |
 | Account | Vacation Fund  |
 | Account | Rainy Day Fund |
 | Account | Rainy Day Fund |
 | Account | Rainy Day Fund |
 +--------------------------*/

PATH_LENGTH

PATH_LENGTH(graph_path)

Description

Gets the number of edges in a graph path.

Definitions

• graph_path: A GRAPH_PATH value that represents the graph path with the edges to count.

Details

Returns NULL if graph_path is NULL.

Return type

INT64

Examples

GRAPH graph_db.FinGraph
MATCH p=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
RETURN PATH_LENGTH(p) AS results

/*---------+
 | results |
 +---------+
 | 2       |
 | 2       |
 | 2       |
 | 2       |
 | 2       |
 | 2       |
 | 2       |
 +---------*/

SOURCE_NODE_ID

SOURCE_NODE_ID(edge_element)

Description

Gets a unique identifier of a graph edge's source node. The unique identifier is only valid for the scope of the query where it's obtained.

Definitions

• edge_element: A GRAPH_ELEMENT value that represents an edge.

Details

Returns NULL if edge_element is NULL.

Return type

STRING

Examples

GRAPH graph_db.FinGraph
MATCH (p:Person)-[o:Owns]->(:Account)
RETURN p.name AS name, SOURCE_NODE_ID(o) AS source_node_id

/*-------------------------------------+
 | name | source_node_id               |
 +------|------------------------------+
 | Alex | mUZpbkdyYXBoLlBlcnNvbgB4kQI= |
 | Dana | mUZpbkdyYXBoLlBlcnNvbgB4kQQ= |
 | Lee  | mUZpbkdyYXBoLlBlcnNvbgB4kQY= |
 +-------------------------------------*/

Note that the actual identifiers obtained may be different from what's shown above.