apoc.agg.first

Details

Syntax

apoc.agg.first(value)

Description

Returns the first value from the given collection.

Arguments

Name

Type

Description

value

ANY

A value to be aggregated.

Returns

ANY

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 (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 (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 (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrix)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixReloaded)
CREATE (Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrixRevolutions)

CREATE (TomH)-[:ACTED_IN {roles:['Joe Fox']}]->(YouveGotMail)
CREATE (TomH)-[:ACTED_IN {roles:['Sam Baldwin']}]->(SleeplessInSeattle);

The following examples return the earliest movie that the above actors starred in using both APOC and Cypher:

apoc.agg.first
MATCH (p:Person)-[:ACTED_IN]->(movie)
WITH p, movie
ORDER BY p, movie.released
RETURN p.name AS person, apoc.agg.first(movie) AS earliestMovie;
Using Cypher’s CALL subquery
MATCH (p:Person)
CALL (p) {
    MATCH (p)-[:ACTED_IN]->(movie)
    RETURN movie ORDER BY movie.released ASC LIMIT 1
}
RETURN p.name AS person, movie AS earliestMovie ORDER BY p
Results
person earliestMovie

"Tom Hanks"

(:Movie {tagline: "What if someone you never met, someone you never saw, someone you never knew was the only someone for you?", title: "Sleepless in Seattle", released: 1993})

"Keanu Reeves"

(:Movie {tagline: "Welcome to the Real World", title: "The Matrix", released: 1999})