GQL operators

Graph Query Language (GQL) supports all GoogleSQL operators, including the following GQL-specific operators:

Graph operators list

Name Summary
Graph logical operators Tests for the truth of a condition in a graph label and produces either TRUE or FALSE.
Graph predicates Tests for the truth of a condition for a graph element and produces TRUE, FALSE, or NULL.
ALL_DIFFERENT predicate In a graph, checks to see if the elements in a list are all different.
IS DESTINATION predicate In a graph, checks to see if a node is or isn't the destination of an edge.
IS SOURCE predicate In a graph, checks to see if a node is or isn't the source of an edge.
SAME predicate In a graph, checks if all graph elements in a list bind to the same node or edge.

Graph logical operators

GoogleSQL supports the following logical operators in element pattern label expressions:

Name Syntax Description
NOT !X Returns TRUE if X isn't included, otherwise, returns FALSE.
OR X | Y Returns TRUE if either X or Y is included, otherwise, returns FALSE.
AND X & Y Returns TRUE if both X and Y are included, otherwise, returns FALSE.

Graph predicates

GoogleSQL supports the following graph-specific predicates in graph expressions. A predicate can produce TRUE, FALSE, or NULL.

ALL_DIFFERENT predicate

ALL_DIFFERENT(element, element[, ...])

Description

In a graph, checks to see if the elements in a list are all different. Returns TRUE if none of the elements in the list equal one another, otherwise FALSE.

Definitions

  • element: The graph pattern variable for a node or edge element.

Details

Produces an error if element is NULL.

Return type

BOOL

Examples

GRAPH graph_db.FinGraph
MATCH
  (a1:Account)-[t1:Transfers]->(a2:Account)-[t2:Transfers]->
  (a3:Account)-[t3:Transfers]->(a4:Account)
WHERE a1.id < a4.id
RETURN
  ALL_DIFFERENT(t1, t2, t3) AS results

/*---------+
 | results |
 +---------+
 | FALSE   |
 | TRUE    |
 | TRUE    |
 +---------*/

IS DESTINATION predicate

node IS [ NOT ] DESTINATION [ OF ] edge

Description

In a graph, checks to see if a node is or isn't the destination of an edge. Can produce TRUE, FALSE, or NULL.

Arguments:

  • node: The graph pattern variable for the node element.
  • edge: The graph pattern variable for the edge element.

Examples

GRAPH graph_db.FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE a IS DESTINATION of transfer
RETURN a.id AS a_id, b.id AS b_id

/*-------------+
 | a_id | b_id |
 +-------------+
 | 16   | 7    |
 | 16   | 7    |
 | 20   | 16   |
 | 7    | 20   |
 | 16   | 20   |
 +-------------*/

GRAPH graph_db.FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE b IS DESTINATION of transfer
RETURN a.id AS a_id, b.id AS b_id

/*-------------+
 | a_id | b_id |
 +-------------+
 | 7    | 16   |
 | 7    | 16   |
 | 16   | 20   |
 | 20   | 7    |
 | 20   | 16   |
 +-------------*/

IS SOURCE predicate

node IS [ NOT ] SOURCE [ OF ] edge

Description

In a graph, checks to see if a node is or isn't the source of an edge. Can produce TRUE, FALSE, or NULL.

Arguments:

  • node: The graph pattern variable for the node element.
  • edge: The graph pattern variable for the edge element.

Examples

GRAPH graph_db.FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE a IS SOURCE of transfer
RETURN a.id AS a_id, b.id AS b_id

/*-------------+
 | a_id | b_id |
 +-------------+
 | 20   | 7    |
 | 7    | 16   |
 | 7    | 16   |
 | 20   | 16   |
 | 16   | 20   |
 +-------------*/

GRAPH graph_db.FinGraph
MATCH (a:Account)-[transfer:Transfers]-(b:Account)
WHERE b IS SOURCE of transfer
RETURN a.id AS a_id, b.id AS b_id

/*-------------+
 | a_id | b_id |
 +-------------+
 | 7    | 20   |
 | 16   | 7    |
 | 16   | 7    |
 | 16   | 20   |
 | 20   | 16   |
 +-------------*/

SAME predicate

SAME (element, element[, ...])

Description

In a graph, checks if all graph elements in a list bind to the same node or edge. Returns TRUE if the elements bind to the same node or edge, otherwise FALSE.

Arguments:

  • element: The graph pattern variable for a node or edge element.

Details

Produces an error if element is NULL.

Example

The following query returns the source and destination IDs for transfers between different accounts:

GRAPH graph_db.FinGraph
MATCH (src:Account)<-[transfer:Transfers]-(dest:Account)
WHERE NOT SAME(src, dest)
RETURN src.id AS source_id, dest.id AS destination_id

/*----------------------------+
 | source_id | destination_id |
 +----------------------------+
 | 7         | 20             |
 | 16        | 7              |
 | 16        | 7              |
 | 16        | 20             |
 | 20        | 16             |
 +----------------------------*/