apoc.meta.schema

Procedure

apoc.meta.schema(config MAP<STRING, ANY>) - examines the given sub-graph and returns metadata as a MAP.

This procedure 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.

Signature

apoc.meta.schema(config = {} :: MAP) :: (value :: MAP)

Input parameters

Name Type Default

config

MAP

{}

Config parameters

This procedure supports the following config parameters:

Table 1. Config parameters
Name Type Default Description

sample

INTEGER

1000

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

Output parameters

Name Type

value

MAP

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 (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 (s0:sameName{id:1}) -[r0:sameName {alfa: 'beta'}] -> (t0:sameName{id:2});
CALL apoc.meta.schema()
YIELD value
UNWIND keys(value) AS key
RETURN key, value[key] AS value;

Note that, in case of relationship type and node label with the same name, the relationships will be distinguished by the suffix " (RELATIONSHIP)"

Table 2. Results
key value

"Movie"

{count: 9, relationships: {ACTED_IN: {count: 41, properties: {roles: {existence: FALSE, type: "LIST", array: TRUE}}, direction: "in", labels: ["Person"]}}, type: "node", properties: {tagline: {existence: FALSE, type: "STRING", indexed: FALSE, unique: FALSE}, title: {existence: FALSE, type: "STRING", indexed: FALSE, unique: FALSE}, released: {existence: FALSE, type: "INTEGER", indexed: FALSE, unique: FALSE}}, labels: []}

"ACTED_IN"

{count: 9, type: "relationship", properties: {roles: {existence: FALSE, type: "LIST", array: TRUE}}}

"Person"

{count: 2, relationships: {ACTED_IN: {count: 9, properties: {roles: {existence: FALSE, type: "LIST", array: TRUE}}, direction: "out", labels: ["Movie"]}}, type: "node", properties: {name: {existence: FALSE, type: "STRING", indexed: FALSE, unique: FALSE}, born: {existence: FALSE, type: "INTEGER", indexed: FALSE, unique: FALSE}}, labels: []}

"sameName (RELATIONSHIP)"

{"count":1,"type":"relationship","properties":{"alfa":{"existence":false,"type":"STRING","array":false}}}

"sameName"

{count: 2, relationships: {"sameName": {count: 1, properties: {alfa: {existence: false, type: "STRING", array: false}}, direction: "out", labels: ["sameName"]}}, type:"node", properties: {id: {existence: false,type: "INTEGER", indexed: false,unique: false}},labels: []}

Sample config usage example

Given the following graph:

CREATE (:Foo), (:Other)-[:REL_0]->(:Other), (:Other)-[:REL_1]->(:Other)<-[:REL_2 {baz: 'baa'}]-(:Other), (:Other {alpha: 'beta'}), (:Other {foo:'bar'})-[:REL_3]->(:Other)

Without sample parameter we receive:

CALL apoc.meta.schema()
YIELD value RETURN value["Other"] as value;
Table 3. Results
value
{
    "count": 8,
    "relationships": {
        "REL_2": {
            "count": 1,
            "properties": {
                "baz": {
                    "existence": false,
                    "type": "STRING",
                    "array": false
                }
            },
            "direction": "out",
            "labels": [
                "Other",
                "Other"
            ]
        },
        "REL_3": {
            "count": 1,
            "properties": {

            },
            "direction": "out",
            "labels": [
                "Other",
                "Other"
            ]
        },
        "REL_0": {
            "count": 1,
            "properties": {

            },
            "direction": "out",
            "labels": [
                "Other",
                "Other"
            ]
        },
        "REL_1": {
            "count": 1,
            "properties": {

            },
            "direction": "out",
            "labels": [
                "Other",
                "Other"
            ]
        }
    },
    "type": "node",
    "properties": {
        "alpha": {
            "existence": false,
            "type": "STRING",
            "indexed": false,
            "unique": false
        },
        "foo": {
            "existence": false,
            "type": "STRING",
            "indexed": false,
            "unique": false
        }
    },
    "labels": []
}

Otherwise, with sample: 2 we might obtain (the result can change):

CALL apoc.meta.schema({sample: 2})
YIELD value RETURN value["Other"] as value
Table 4. Results
value
{
  "count": 8,
  "relationships": {
    "REL_1": {
      "count": 1,
      "properties": {},
      "direction": "out",
      "labels": [
        "Other",
        "Other"
      ]
    }
  },
  "type": "node",
  "properties": {
    "alpha": {
      "existence": false,
      "type": "STRING",
      "indexed": false,
      "unique": false
    }
  },
  "labels": []
}