apoc.cypher.runFirstColumnSingle

Details
Syntax	`apoc.cypher.runFirstColumnSingle(statement, params)`
Description	Runs the given statement with the given parameters and returns the first element of the first column.
Arguments	Name	Type	Description
	`statement`	`STRING`	The Cypher query to execute.
	`params`	`MAP`	The parameters needed for input to the given Cypher query.
Returns	`ANY`

This function is not considered safe to run from multiple threads. It is therefore not supported by the parallel runtime (introduced in Neo4j 5.13). For more information, see the Cypher Manual → Parallel runtime.

Usage Examples

The examples in this section are based on the following sample graph:

CREATE (Keanu:Person {name:'Keanu Reeves', born:1964})
CREATE (TomH:Person {name:'Tom Hanks', born:1956})
CREATE (TomT:Person {name:'Tom Tykwer', born:1965})

CREATE (TheMatrix:Movie {title:'The Matrix', released:1999, tagline:'Welcome to the Real World'})
CREATE (TheMatrixReloaded:Movie {title:'The Matrix Reloaded', released:2003, tagline:'Free your mind'})
CREATE (TheMatrixRevolutions:Movie {title:'The Matrix Revolutions', released:2003, tagline:'Everything that has a beginning has an end'})
CREATE (SomethingsGottaGive:Movie {title:"Something's Gotta Give", released:2003})
CREATE (TheDevilsAdvocate:Movie {title:"The Devil's Advocate", released:1997, tagline:'Evil has its winning ways'})

CREATE (YouveGotMail:Movie {title:"You've Got Mail", released:1998, tagline:'At odds in life... in love on-line.'})
CREATE (SleeplessInSeattle:Movie {title:'Sleepless in Seattle', released:1993, tagline:'What if someone you never met, someone you never saw, someone you never knew was the only someone for you?'})
CREATE (ThatThingYouDo:Movie {title:'That Thing You Do', released:1996, tagline:'In every life there comes a time when that thing you dream becomes that thing you do'})
CREATE (CloudAtlas:Movie {title:'Cloud Atlas', released:2012, tagline:'Everything is connected'})

CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrix)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixReloaded)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixRevolutions)
CREATE (Keanu)-[:ACTED_IN {roles:['Julian Mercer']}]->(SomethingsGottaGive)
CREATE (Keanu)-[:ACTED_IN {roles:['Kevin Lomax']}]->(TheDevilsAdvocate)

CREATE (TomH)-[:ACTED_IN {roles:['Joe Fox']}]->(YouveGotMail)
CREATE (TomH)-[:ACTED_IN {roles:['Sam Baldwin']}]->(SleeplessInSeattle)
CREATE (TomH)-[:ACTED_IN {roles:['Mr. White']}]->(ThatThingYouDo)
CREATE (TomH)-[:ACTED_IN {roles:['Zachry', 'Dr. Henry Goose', 'Isaac Sachs', 'Dermot Hoggins']}]->(CloudAtlas)
CREATE (TomT)-[:DIRECTED]->(CloudAtlas);

This function is useful for executing Cypher statements that have a dynamic node label or relationship type and return one row of one column. For example, we can return a stream of all the labels and their counts by running the following query:

CALL db.labels()
YIELD label
RETURN label,
       apoc.cypher.runFirstColumnSingle("MATCH (:" + label + ") RETURN count(*)", {}) AS count;

Results
label	count
"Person"	3
"Movie"	9

And we can return a stream of all relationship types and their counts, by running the following query:

CALL db.relationshipTypes()
YIELD relationshipType
RETURN relationshipType,
       apoc.cypher.runFirstColumnSingle("MATCH ()-[:" + relationshipType + "]->() RETURN count(*)", {}) AS count;

Results
relationshipType	count
"ACTED_IN"	9
"DIRECTED"	1

More documentation of apoc.cypher.runFirstColumnSingle