apoc.cypher.runFirstColumnSingle

Function APOC Core

apoc.cypher.runFirstColumnSingle(statement, params) - executes statement with given parameters, returns first element of the first column only, params are available as identifiers

Signature

apoc.cypher.runFirstColumnSingle(cypher :: STRING?, params :: MAP?) :: (ANY?)

Input parameters

Name Type Default

cypher

STRING?

null

params

MAP?

null

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;
Table 1. 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;
Table 2. Results
relationshipType count

"ACTED_IN"

9

"DIRECTED"

1

More documentation of apoc.cypher.runFirstColumnSingle