GQL functions

GoogleSQL for Spanner 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.
IS_ACYCLIC Checks if a graph path has a repeating node.
IS_FIRST Returns true if this row is in the first k rows (1-based) within the window.
IS_SIMPLE Checks if a graph path is simple.
IS_TRAIL Checks if a graph path has a repeating edge.
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 Creates a graph path from a list of graph elements.
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.
PROPERTY_NAMES Gets the property names associated with a graph element.
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.

Arguments

  • edge_element: A GRAPH_ELEMENT value that represents an edge.

Details

Returns NULL if edge_element is NULL.

Return type

STRING

Examples

GRAPHFinGraph
MATCH(:Person)-[o:Owns]->(a:Account)
RETURNa.idASaccount_id,DESTINATION_NODE_ID(o)ASdestination_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

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETes=EDGES(p)
RETURNARRAY_CONCAT(ARRAY_TRANSFORM(es,e->e.Id),[dst.Id])asids_in_path
/*-------------+
 | ids_in_path |
 +-------------+
 | [16,20,7] |
 +-------------+
 | [20,7,16] |
 +-------------+
 | [20,7,16] |
 +-------------+
 | [16,20,16] |
 +-------------+
 | [7,16,20] |
 +-------------+
 | [7,16,20] |
 +-------------+
 | [20,16,20] |
 +-------------*/

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.

Arguments

  • element: A GRAPH_ELEMENT value.

Details

Returns NULL if element is NULL.

Return type

STRING

Examples

GRAPHFinGraph
MATCH(p:Person)-[o:Owns]->(:Account)
RETURNp.nameASname,ELEMENT_ID(p)ASnode_element_id,ELEMENT_ID(o)ASedge_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.

IS_ACYCLIC

IS_ACYCLIC(graph_path)

Description

Checks if a graph path has a repeating node. Returns TRUE if a repetition isn't found, otherwise returns FALSE.

Definitions

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

Details

Two nodes are considered equal if they compare as equal.

Returns NULL if graph_path is NULL.

Return type

BOOL

Examples

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
RETURNsrc.idASsource_account_id,IS_ACYCLIC(p)ASis_acyclic_path
/*-------------------------------------+
 | source_account_id | is_acyclic_path |
 +-------------------------------------+
 | 16 | TRUE |
 | 20 | TRUE |
 | 20 | TRUE |
 | 16 | FALSE |
 | 7 | TRUE |
 | 7 | TRUE |
 | 20 | FALSE |
 +-------------------------------------*/

IS_FIRST

IS_FIRST(k)
OVERover_clause
over_clause:
([window_specification])
window_specification:
[PARTITIONBYpartition_expression[,...]]
[ORDERBYexpression[{ASC|DESC}][,...]]

Description

Returns true if the current row is in the first k rows (1-based) in the window; otherwise, returns false. This function doesn't require the ORDER BY clause.

Details

  • The k value must be positive; otherwise, a runtime error is raised.
  • If any rows are tied or if ORDER BY is omitted, the result is non-deterministic. If the ORDER BY clause is unspecified or if all rows are tied, the result is equivalent to ANY-k.

Return Type

BOOL

IS_SIMPLE

IS_SIMPLE(graph_path)

Description

Checks if a graph path is simple. Returns TRUE if the path has no repeated nodes, or if the only repeated nodes are its head and tail. Otherwise, returns FALSE.

Definitions

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

Details

Returns NULL if graph_path is NULL.

Return type

BOOL

Examples

GRAPHFinGraph
MATCHp=(a1:Account)-[t1:Transferswheret1.amount > 200]->
(a2:Account)-[t2:Transferswheret2.amount > 200]->
(a3:Account)-[t3:Transferswheret3.amount > 100]->(a4:Account)
RETURN
IS_SIMPLE(p)ASis_simple_path,
a1.idasa1_id,a2.idasa2_id,a3.idasa3_id,a4.idasa4_id
/*----------------+-------+-------+-------+-------+
 | is_simple_path | a1_id | a2_id | a3_id | a4_id |
 +----------------+-------+-------+-------+-------+
 | TRUE | 7 | 16 | 20 | 7 |
 | TRUE | 16 | 20 | 7 | 16 |
 | FALSE | 7 | 16 | 20 | 16 |
 | TRUE | 20 | 7 | 16 | 20 |
 +----------------+-------+-------+-------+-------*/

IS_TRAIL

IS_TRAIL(graph_path)

Description

Checks if a graph path has a repeating edge. Returns TRUE if a repetition isn't found, otherwise returns FALSE.

Definitions

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

Details

Returns NULL if graph_path is NULL.

Return type

BOOL

Examples

GRAPHFinGraph
MATCH
p=(a1:Account)-[t1:Transfers]->(a2:Account)-[t2:Transfers]->
(a3:Account)-[t3:Transfers]->(a4:Account)
WHEREa1.id < a4.id
RETURN
IS_TRAIL(p)ASis_trail_path,t1.idast1_id,t2.idast2_id,t3.idast3_id
/*---------------+-------+-------+-------+
 | is_trail_path | t1_id | t2_id | t3_id |
 +---------------+-------+-------+-------+
 | FALSE | 16 | 20 | 16 |
 | TRUE | 7 | 16 | 20 |
 | TRUE | 7 | 16 | 20 |
 +---------------+-------+-------+-------*/

LABELS

LABELS(element)

Description

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

Arguments

  • 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

GRAPHFinGraph
MATCH(n:Person|Account)
RETURNLABELS(n)ASlabel,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

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETns=NODES(p)
RETURN
JSON_QUERY(TO_JSON(ns)[0],'$.labels')ASlabels,
JSON_QUERY(TO_JSON(ns)[0],'$.properties.nick_name')ASnick_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

PATH(graph_element[,...])

Description

Creates a graph path from a list of graph elements.

Definitions

  • graph_element: A GRAPH_ELEMENT value that represents a graph element, such as a node or edge, to add to a graph path.

Details

This function produces an error if:

  • A graph element is NULL.
  • Nodes aren't interleaved with edges.
  • An edge doesn't connect to neighboring nodes.

Return type

GRAPH_PATH

Examples

GRAPHFinGraph
MATCH(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETp=PATH(src,t1,mid,t2,dst)
RETURN
JSON_QUERY(TO_JSON(p)[0],'$.labels')ASelement_a,
JSON_QUERY(TO_JSON(p)[1],'$.labels')ASelement_b,
JSON_QUERY(TO_JSON(p)[2],'$.labels')ASelement_c
/*-------------------------------------------+
 | element_a | element_b | element_c |
 +-------------------------------------------+
 | ["Account"] | ["Transfers"] | ["Account"] |
 | ... | ... | ... |
 +-------------------------------------------*/

-- Error: in 'p', a graph element is NULL.
GRAPHFinGraph
MATCH(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETp=PATH(src,NULL,mid,t2,dst)
RETURNTO_JSON(p)ASresults

-- Error: in 'p', 'src' and 'mid' are nodes that should be interleaved with an
-- edge.
GRAPHFinGraph
MATCH(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETp=PATH(src,mid,t2,dst)
RETURNTO_JSON(p)ASresults

-- Error: in 'p', 't2' is an edge that doesn't connect to a neighboring node on
-- the right.
GRAPHFinGraph
MATCH(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETp=PATH(src,t2,mid)
RETURNTO_JSON(p)ASresults

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

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETf=PATH_FIRST(p)
RETURN
LABELS(f)ASlabels,
f.nick_nameASnick_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

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
LETf=PATH_LAST(p)
RETURN
LABELS(f)ASlabels,
f.nick_nameASnick_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

GRAPHFinGraph
MATCHp=(src:Account)-[t1:Transfers]->(mid:Account)-[t2:Transfers]->(dst:Account)
RETURNPATH_LENGTH(p)ASresults
/*---------+
 | results |
 +---------+
 | 2 |
 | 2 |
 | 2 |
 | 2 |
 | 2 |
 | 2 |
 | 2 |
 +---------*/

PROPERTY_NAMES

PROPERTY_NAMES(element)

Description

Gets the name of each property associated with a graph element and preserves the original case of each name.

Arguments

  • element: A GRAPH_ELEMENT value.

Details

Returns NULL if element is NULL.

Return type

ARRAY<STRING>

Examples

GRAPHFinGraph
MATCH(n:Person|Account)
RETURNPROPERTY_NAMES(n)ASproperty_names,n.id
/*-----------------------------------------------+
 | label | id |
 +-----------------------------------------------+
 | [create_time, id, is_blocked, nick_name] | 7 |
 | [create_time, id, is_blocked, nick_name] | 16 |
 | [create_time, id, is_blocked, nick_name] | 20 |
 | [birthday, city, country, id, name] | 1 |
 | [birthday, city, country, id, name] | 2 |
 | [birthday, city, country, id, name] | 3 |
 +-----------------------------------------------*/

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.

Arguments

  • edge_element: A GRAPH_ELEMENT value that represents an edge.

Details

Returns NULL if edge_element is NULL.

Return type

STRING

Examples

GRAPHFinGraph
MATCH(p:Person)-[o:Owns]->(:Account)
RETURNp.nameASname,SOURCE_NODE_ID(o)ASsource_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.

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Last updated 2025年11月26日 UTC.