apoc.path.combine

Function APOC Core

apoc.path.combine(path1, path2) - combines the paths into one if the connecting node matches

Signature

apoc.path.combine(first :: PATH?, second :: PATH?) :: (PATH?)

Input parameters

Name	Type	Default
first	PATH?	null
second	PATH?	null

Name

Type

Default

first

PATH?

null

second

PATH?

null

Usage Examples

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

MERGE (manUtd:Club {name: 'Man Utd'})
MERGE (juventus:Club {name: 'Juventus'})
MERGE (flamengo:Club {name: 'Flamengo'})

MERGE (premierLeague:League {name: 'Premier League'})
MERGE (serieA:League {name: 'Serie A'})
MERGE (brasileirao:League {name: 'Brasileirão'})

MERGE (england:Country {name: 'England'})
MERGE (brazil:Country {name: 'Brazil'})

MERGE (uefa:Confederation {name: 'UEFA'})

MERGE (manUtd)-[:IN_LEAGUE]->(premierLeague)
MERGE (premierLeague)-[:IN_COUNTRY]->(england)
MERGE (england)-[:IN_CONFEDERATION]->(uefa)

MERGE (juventus)-[:IN_LEAGUE]->(serieA)

MERGE (flamengo)-[:IN_LEAGUE]->(brasileirao)
MERGE (brasileirao)-[:IN_COUNTRY]->(brazil);

If we want to create a path from a query that contains two OPTIONAL MATCH clauses, we can use the apoc.path.combine function.

The following returns a path that combines the (club)-[:IN_LEAGUE]→(league) and (league)-[:IN_COUNTRY]→(country) paths:

MATCH (club:Club)
OPTIONAL MATCH path1 = (club)-[:IN_LEAGUE]->(league)
OPTIONAL MATCH path2 = (league)-[:IN_COUNTRY]->(country)
RETURN club.name, apoc.path.combine(path1, path2) AS path
ORDER BY length(path);

Table 1. Results
club.name	path
"Juventus"	(:Club {name: "Juventus"})-[:IN_LEAGUE]→(:League {name: "Serie A"})
"Man Utd"	(:Club {name: "Man Utd"})-[:IN_LEAGUE]→(:League {name: "Premier League"})-[:IN_COUNTRY]→(:Country {name: "England"})
"Flamengo"	(:Club {name: "Flamengo"})-[:IN_LEAGUE]→(:League {name: "Brasileirão"})-[:IN_COUNTRY]→(:Country {name: "Brazil"})

If we want to combine more than two OPTIONAL MATCH paths, see apoc.path.create.