apoc.meta.relTypeProperties

Procedure APOC Core

apoc.meta.relTypeProperties()

Signature

apoc.meta.relTypeProperties(config = {} :: MAP?) :: (relType :: STRING?, sourceNodeLabels :: LIST? OF STRING?, targetNodeLabels :: LIST? OF STRING?, propertyName :: STRING?, propertyTypes :: LIST? OF STRING?, mandatory :: BOOLEAN?, propertyObservations :: INTEGER?, totalObservations :: INTEGER?)

Input parameters

Name Type Default

config

MAP?

{}

Config parameters

This procedure supports the following config parameters:

Table 1. Config parameters
Name Type Default Description

includeLabels

List<String>

[]

Node labels to include. Default is to include all node labels.

includeRels

List<String>

[]

Relationship types to include. Default is to include all relationship types.

excludeLabels

List<String>

[]

Node labels to exclude. Default is to include all node labels.

excludeRels

List<String>

[]

Relationship types to exclude. Default is to include all relationship types.

sample

Long

1000

Number of nodes to skip, e.g. a sample of 1000 will read every 1000th node.

maxRels

Long

100

Number of relationships to read per sampled node.
Table 2. Deprecated parameters
Name Type Default Description

labels

List<String>

[]

Deprecated, use includeLabels.

rels

List<String>

[]

Deprecated, use includeRels.

excludes

List<String>

[]

Deprecated, use excludeLabels.

Output parameters

Name Type

relType

STRING?

sourceNodeLabels

LIST? OF STRING?

targetNodeLabels

LIST? OF STRING?

propertyName

STRING?

propertyTypes

LIST? OF STRING?

mandatory

BOOLEAN?

propertyObservations

INTEGER?

totalObservations

INTEGER?

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 (LillyW:Person {name:'Lilly Wachowski', born:1967})

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 (LillyW)-[:DIRECTED]->(TheMatrix);

We can return the metadata of the database from a sample of the database contents, by running the following query:

CALL apoc.meta.relTypeProperties();
Table 3. Results
relType sourceNodeLabels targetNodeLabels propertyName propertyTypes mandatory propertyObservations totalObservations

":`ACTED_IN`"

["Person"]

["Movie"]

"roles"

["StringArray"]

FALSE

9

9

":`DIRECTED`"

["Person"]

["Movie"]

NULL

NULL

FALSE

0

1

We can return metadata for a subset of relationship types by specifying the rels config parameter. The following returns the metadata for the ACTED_IN label:

CALL apoc.meta.relTypeProperties({rels: ["ACTED_IN"]});
Table 4. Results
relType sourceNodeLabels targetNodeLabels propertyName propertyTypes mandatory propertyObservations totalObservations

":`ACTED_IN`"

["Person"]

["Movie"]

"roles"

["StringArray"]

FALSE

9

9

We can control the number of relationships sampled by specifying the maxRels parameter. The following returns metadata based on sampling up to 3 relationships per relationship type:

CALL apoc.meta.relTypeProperties({maxRels: 3});
Table 5. Results
relType sourceNodeLabels targetNodeLabels propertyName propertyTypes mandatory propertyObservations totalObservations

":`ACTED_IN`"

["Person"]

["Movie"]

"roles"

["StringArray"]

FALSE

3

9

":`DIRECTED`"

["Person"]

["Movie"]

NULL

NULL

FALSE

0

1