apoc.export.cypher.query

Procedure APOC Core

apoc.export.cypher.query(query,file,config) - exports nodes and relationships from the cypher statement incl. indexes as cypher statements to the provided file

Signature

apoc.export.cypher.query(query :: STRING?, file =  :: STRING?, config = {} :: MAP?) :: (file :: STRING?, batches :: INTEGER?, source :: STRING?, format :: STRING?, nodes :: INTEGER?, relationships :: INTEGER?, properties :: INTEGER?, time :: INTEGER?, rows :: INTEGER?, batchSize :: INTEGER?, cypherStatements :: STRING?, nodeStatements :: STRING?, relationshipStatements :: STRING?, schemaStatements :: STRING?, cleanupStatements :: STRING?)

Input parameters

Name Type Default

query

STRING?

null

file

STRING?

config

MAP?

{}

Config parameters

The procedure support the following config parameters:

Table 1. Config parameters
name type default description

writeNodeProperties

boolean

false

if true export properties too.

stream

boolean

false

stream the json directly to the client into the data field

format

String

cypher-shell

Export format. The following values are supported:

  • cypher-shell - for import with Cypher Shell

  • neo4j-shell - for import with Neo4j Shell and partly the apoc.cypher.runFile procedure

  • plain - exports plain Cypher without begin, commit, or await commands. For import with Neo4j Browser

cypherFormat

String

create

Cypher update operation type. The following values are supported:

  • create - only uses the CREATE clause

  • updateAll - uses MERGE instead of CREATE

  • addStructure - uses MATCH for nodes and MERGE for relationships

  • updateStructure - uses MERGE and MATCH for nodes and relationships

separateFiles

boolean

false

Export to separate files? This is useful for later use with the apoc.cypher.runFiles and apoc.cypher.runSchemaFiles procedures.

useOptimizations

Map

{type: "UNWIND_BATCH", unwindBatchSize: 20}

Optimizations to use for Cypher statement generation. type supports the following values:

  • NONE - exports the file with CREATE statement

  • UNWIND_BATCH - exports the file by batching the entities with the UNWIND method as explained in Michael Hunger’s article on fast batched writes.

  • UNWIND_BATCH_PARAMS - similar to UNWIND_BATCH, but also uses parameters where appropriate

awaitForIndexes

Long

300

Timeout to use for db.awaitIndexes when using format: "cypher-shell"

Output parameters

Name Type

file

STRING?

batches

INTEGER?

source

STRING?

format

STRING?

nodes

INTEGER?

relationships

INTEGER?

properties

INTEGER?

time

INTEGER?

rows

INTEGER?

batchSize

INTEGER?

cypherStatements

STRING?

nodeStatements

STRING?

relationshipStatements

STRING?

schemaStatements

STRING?

cleanupStatements

STRING?

Exporting to a file

By default exporting to the file system is disabled. We can enable it by setting the following property in apoc.conf:

apoc.conf
apoc.export.file.enabled=true

If we try to use any of the export procedures without having first set this property, we’ll get the following error message:

Failed to invoke procedure: Caused by: java.lang.RuntimeException: Export to files not enabled, please set apoc.export.file.enabled=true in your neo4j.conf

Export files are written to the import directory, which is defined by the dbms.directories.import property. This means that any file path that we provide is relative to this directory. If we try to write to an absolute path, such as /tmp/filename, we’ll get an error message similar to the following one:

Failed to invoke procedure: Caused by: java.io.FileNotFoundException: /path/to/neo4j/import/tmp/fileName (No such file or directory)

We can enable writing to anywhere on the file system by setting the following property in apoc.conf:

apoc.conf
apoc.import.file.use_neo4j_config=false

Neo4j will now be able to write anywhere on the file system, so be sure that this is your intention before setting this property.

Exporting a stream

If we don’t want to export to a file, we can stream results back in the data column instead by passing a file name of null and providing the stream:true config.

Usage Examples

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

CREATE (TheMatrix:Movie {title:'The Matrix', released:1999, tagline:'Welcome to the Real World'})
CREATE (Keanu:Person {name:'Keanu Reeves', born:1964})
CREATE (Carrie:Person {name:'Carrie-Anne Moss', born:1967})
CREATE (Laurence:Person {name:'Laurence Fishburne', born:1961})
CREATE (Hugo:Person {name:'Hugo Weaving', born:1960})
CREATE (LillyW:Person {name:'Lilly Wachowski', born:1967})
CREATE (LanaW:Person {name:'Lana Wachowski', born:1965})
CREATE (JoelS:Person {name:'Joel Silver', born:1952})
CREATE
(Keanu)-[:ACTED_IN {roles:['Neo']}]->(TheMatrix),
(Carrie)-[:ACTED_IN {roles:['Trinity']}]->(TheMatrix),
(Laurence)-[:ACTED_IN {roles:['Morpheus']}]->(TheMatrix),
(Hugo)-[:ACTED_IN {roles:['Agent Smith']}]->(TheMatrix),
(LillyW)-[:DIRECTED]->(TheMatrix),
(LanaW)-[:DIRECTED]->(TheMatrix),
(JoelS)-[:PRODUCED]->(TheMatrix);

The Neo4j Browser visualization below shows the imported graph:

play movies
Figure 1. Movies Graph Visualization

The export to Cypher procedures all support writing to multiple files or multiple columns. We can enable this mode by passing in the config separateFiles: true

The following query exports all the ACTED_IN relationships and corresponding nodes into files with an actedIn prefix

CALL apoc.export.cypher.query(
  "MATCH ()-[r:ACTED_IN]->()
   RETURN *",
  "actedIn.cypher",
  { format: "cypher-shell", separateFiles: true })
YIELD file, batches, source, format, nodes, relationships, time, rows, batchSize
RETURN file, batches, source, format, nodes, relationships, time, rows, batchSize;
Table 2. Results
file batches source format nodes relationships time rows batchSize

"actedIn.cypher"

1

"statement: nodes(10), rels(8)"

"cypher"

10

8

3

18

20000

This will result in the following files being created:

Table 3. Results
Name Size in bytes Number of lines

actedIn.cleanup.cypher

234

6

actedIn.nodes.cypher

893

6

actedIn.relationships.cypher

757

6

actedIn.schema.cypher

109

3

Each of those files contains one particular part of the graph. Let’s have a look at their content:

actedIn.cleanup.cypher
:begin
MATCH (n:`UNIQUE IMPORT LABEL`)  WITH n LIMIT 20000 REMOVE n:`UNIQUE IMPORT LABEL` REMOVE n.`UNIQUE IMPORT ID`;
:commit
:begin
DROP CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.`UNIQUE IMPORT ID`) IS UNIQUE;
:commit
actedIn.nodes.cypher
:begin
UNWIND [{_id:28, properties:{tagline:"Welcome to the Real World", title:"The Matrix", released:1999}}, {_id:37, properties:{tagline:"Welcome to the Real World", title:"The Matrix", released:1999}}] AS row
CREATE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) SET n += row.properties SET n:Movie;
UNWIND [{_id:31, properties:{born:1961, name:"Laurence Fishburne"}}, {_id:30, properties:{born:1967, name:"Carrie-Anne Moss"}}, {_id:42, properties:{born:1964, name:"Keanu Reeves"}}, {_id:0, properties:{born:1960, name:"Hugo Weaving"}}, {_id:29, properties:{born:1964, name:"Keanu Reeves"}}, {_id:38, properties:{born:1960, name:"Hugo Weaving"}}, {_id:43, properties:{born:1967, name:"Carrie-Anne Moss"}}, {_id:57, properties:{born:1961, name:"Laurence Fishburne"}}] AS row
CREATE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) SET n += row.properties SET n:Person;
:commit
actedIn.relationships.cypher
:begin
UNWIND [{start: {_id:31}, end: {_id:28}, properties:{roles:["Morpheus"]}}, {start: {_id:42}, end: {_id:37}, properties:{roles:["Neo"]}}, {start: {_id:38}, end: {_id:37}, properties:{roles:["Agent Smith"]}}, {start: {_id:0}, end: {_id:28}, properties:{roles:["Agent Smith"]}}, {start: {_id:29}, end: {_id:28}, properties:{roles:["Neo"]}}, {start: {_id:43}, end: {_id:37}, properties:{roles:["Trinity"]}}, {start: {_id:30}, end: {_id:28}, properties:{roles:["Trinity"]}}, {start: {_id:57}, end: {_id:37}, properties:{roles:["Morpheus"]}}] AS row
MATCH (start:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.start._id})
MATCH (end:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.end._id})
CREATE (start)-[r:ACTED_IN]->(end) SET r += row.properties;
:commit
actedIn.schema.cypher
:begin
CREATE CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.`UNIQUE IMPORT ID`) IS UNIQUE;
:commit

We can then apply these files to our destination Neo4j instance, either by streaming their contents into Cypher Shell or by using the procedures described in Running Cypher fragments.

We can also use the separateFiles when returning a stream of export statements. The results will appear in columns named nodeStatements, relationshipStatements, cleanupStatements, and schemaStatements rather than cypherStatements.

The following query returns a stream all the ACTED_IN relationships and corresponding nodes

CALL apoc.export.cypher.query(
  "MATCH ()-[r:ACTED_IN]->()
   RETURN *",
  null,
  { format: "cypher-shell", separateFiles: true })
YIELD nodes, relationships, properties, nodeStatements, relationshipStatements, cleanupStatements, schemaStatements
RETURN nodes, relationships, properties, nodeStatements, relationshipStatements, cleanupStatements, schemaStatements;
Table 4. Results
nodes relationships properties nodeStatements relationshipStatements cleanupStatements schemaStatements

10

8

30

":begin UNWIND [{_id:28, properties:{tagline:\"Welcome to the Real World\", title:\"The Matrix\", released:1999}}, {_id:37, properties:{tagline:\"Welcome to the Real World\", title:\"The Matrix\", released:1999}}] AS row CREATE (n:`UNIQUE IMPORT LABEL`{UNIQUE IMPORT ID: row._id}) SET n += row.properties SET n:Movie; UNWIND [{_id:0, properties:{born:1960, name:\"Hugo Weaving\"}}, {_id:42, properties:{born:1964, name:\"Keanu Reeves\"}}, {_id:31, properties:{born:1961, name:\"Laurence Fishburne\"}}, {_id:29, properties:{born:1964, name:\"Keanu Reeves\"}}, {_id:30, properties:{born:1967, name:\"Carrie-Anne Moss\"}}, {_id:43, properties:{born:1967, name:\"Carrie-Anne Moss\"}}, {_id:38, properties:{born:1960, name:\"Hugo Weaving\"}}, {_id:57, properties:{born:1961, name:\"Laurence Fishburne\"}}] AS row CREATE (n:`UNIQUE IMPORT LABEL`{UNIQUE IMPORT ID: row._id}) SET n += row.properties SET n:Person; :commit "

":begin UNWIND [{start: {_id:31}, end: {_id:28}, properties:{roles:[\"Morpheus\"]}}, {start: {_id:38}, end: {_id:37}, properties:{roles:[\"Agent Smith\"]}}, {start: {_id:0}, end: {_id:28}, properties:{roles:[\"Agent Smith\"]}}, {start: {_id:30}, end: {_id:28}, properties:{roles:[\"Trinity\"]}}, {start: {_id:29}, end: {_id:28}, properties:{roles:[\"Neo\"]}}, {start: {_id:43}, end: {_id:37}, properties:{roles:[\"Trinity\"]}}, {start: {_id:42}, end: {_id:37}, properties:{roles:[\"Neo\"]}}, {start: {_id:57}, end: {_id:37}, properties:{roles:[\"Morpheus\"]}}] AS row MATCH (start:`UNIQUE IMPORT LABEL`{UNIQUE IMPORT ID: row.start._id}) MATCH (end:`UNIQUE IMPORT LABEL`{UNIQUE IMPORT ID: row.end._id}) CREATE (start)-[r:ACTED_IN]→(end) SET r += row.properties; :commit "

":begin MATCH (n:`UNIQUE IMPORT LABEL`) WITH n LIMIT 20000 REMOVE n:`UNIQUE IMPORT LABEL` REMOVE n.UNIQUE IMPORT ID; :commit :begin DROP CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.UNIQUE IMPORT ID) IS UNIQUE; :commit "

":begin CREATE CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.UNIQUE IMPORT ID) IS UNIQUE; :commit "

We can then copy/paste the content of each of these columns (excluding the double quotes) into a Cypher Shell session, or into a local file that we stream into a Cypher Shell session. If we want to export Cypher statements that can be pasted into the Neo4j Browser query editor, we need to use the config format: "plain".