apoc.export.cypher.data

Procedure APOC Core

apoc.export.cypher.data(nodes,rels,file,config) - exports given nodes and relationships incl. indexes as cypher statements to the provided file

Signature

apoc.export.cypher.data(nodes :: LIST? OF NODE?, rels :: LIST? OF RELATIONSHIP?, 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

nodes

LIST? OF NODE?

null

rels

LIST? OF RELATIONSHIP?

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 generate Cypher statements using the CREATE, MATCH and MERGE clauses. The format is configured by the cypherFormat parameter. The following values are supported:

  • create - only uses the CREATE clause (default)

  • updateAll - uses MERGE instead of CREATE

  • addStructure - uses MATCH for nodes and MERGE for relationships

  • updateStructure - uses MERGE and MATCH for nodes and relationships

If we’re exporting a database for the first time we should use the default create format, but for subsequent exports the other formats may be more suitable.

The following exports the ACTED_IN relationships and surrounding nodes to export-cypher-format-create.cypher using the create format

MATCH (person)-[r:ACTED_IN]->(movie)
WITH collect(DISTINCT person) + collect(DISTINCT  movie) AS importNodes, collect(r) AS importRels
CALL apoc.export.cypher.data(importNodes, importRels,
  "export-cypher-format-create.cypher",
  { format: "plain", cypherFormat: "create" })
YIELD file, batches, source, format, nodes, relationships, properties, time, rows, batchSize
RETURN file, batches, source, format, nodes, relationships, properties, time, rows, batchSize;
Table 2. Results
file batches source format nodes relationships properties time rows batchSize

"export-cypher-format-create.cypher"

1

"data: nodes(5), rels(4)"

"cypher"

5

4

15

2

9

20000

export-cypher-format-create.cypher
CREATE CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.`UNIQUE IMPORT ID`) IS UNIQUE;
UNWIND [{_id:0, 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:7, properties:{born:1967, name:"Carrie-Anne Moss"}},
        {_id:80, properties:{born:1960, name:"Hugo Weaving"}},
        {_id:27, properties:{born:1964, name:"Keanu Reeves"}},
        {_id:44, 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;

UNWIND [{start: {_id:27}, end: {_id:0}, properties:{roles:["Neo"]}},
        {start: {_id:7}, end: {_id:0}, properties:{roles:["Trinity"]}},
        {start: {_id:44}, end: {_id:0}, properties:{roles:["Morpheus"]}},
        {start: {_id:80}, end: {_id:0}, properties:{roles:["Agent Smith"]}}] 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;

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

The creation of all graph entities uses the Cypher CREATE clause. If those entities may already exist in the destination database, we may choose to use another format. Using cypherFormat: "updateAll" means that the MERGE clause will be used instead of CREATE when creating entities.

The following exports the ACTED_IN relationships and surrounding nodes to export-cypher-format-create.cypher using the updateAll format

MATCH (person)-[r:ACTED_IN]->(movie)
WITH collect(DISTINCT person) + collect(DISTINCT  movie) AS importNodes, collect(r) AS importRels
CALL apoc.export.cypher.data(importNodes, importRels,
  "export-cypher-format-updateAll.cypher",
  { format: "plain", cypherFormat: "updateAll" })
YIELD file, batches, source, format, nodes, relationships, properties, time, rows, batchSize
RETURN file, batches, source, format, nodes, relationships, properties, time, rows, batchSize;
Table 3. Results
file batches source format nodes relationships properties time rows batchSize

"export-cypher-format-updateAll.cypher"

1

"data: nodes(5), rels(4)"

"cypher"

5

4

15

8

9

20000

export-cypher-format-updateAll.cypher
CREATE CONSTRAINT ON (node:`UNIQUE IMPORT LABEL`) ASSERT (node.`UNIQUE IMPORT ID`) IS UNIQUE;
UNWIND [{_id:0, properties:{tagline:"Welcome to the Real World", title:"The Matrix", released:1999}}] AS row
MERGE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) SET n += row.properties SET n:Movie;

UNWIND [{_id:80, properties:{born:1960, name:"Hugo Weaving"}},
        {_id:7, properties:{born:1967, name:"Carrie-Anne Moss"}},
        {_id:44, properties:{born:1961, name:"Laurence Fishburne"}},
        {_id:27, properties:{born:1964, name:"Keanu Reeves"}}] AS row
MERGE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) SET n += row.properties SET n:Person;

UNWIND [{start: {_id:27}, end: {_id:0}, properties:{roles:["Neo"]}},
        {start: {_id:7}, end: {_id:0}, properties:{roles:["Trinity"]}},
        {start: {_id:44}, end: {_id:0}, properties:{roles:["Morpheus"]}},
        {start: {_id:80}, end: {_id:0}, properties:{roles:["Agent Smith"]}}] AS row
MATCH (start:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.start._id})
MATCH (end:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.end._id})
MERGE (start)-[r:ACTED_IN]->(end) SET r += row.properties;

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

If we already have the nodes in our destination database, we can use cypherFormat: "addStructure" to create Cypher CREATE statements for just the relationships.

The following exports the ACTED_IN relationships and surrounding nodes to export-cypher-format-addStructure.cypher using the addStructure format

MATCH (person)-[r:ACTED_IN]->(movie)
WITH collect(DISTINCT person) + collect(DISTINCT  movie) AS importNodes, collect(r) AS importRels
CALL apoc.export.cypher.data(importNodes, importRels,
  "export-cypher-format-addStructure.cypher",
  { format: "plain", cypherFormat: "addStructure" })
YIELD file, batches, source, format, nodes, relationships, properties, time, rows, batchSize
RETURN file, batches, source, format, nodes, relationships, properties, time, rows, batchSize;
Table 4. Results
file batches source format nodes relationships properties time rows batchSize

"export-cypher-format-addStructure.cypher"

1

"data: nodes(5), rels(4)"

"cypher"

5

4

15

4

9

20000

export-cypher-format-addStructure.cypher
UNWIND [{_id:0, properties:{tagline:"Welcome to the Real World", title:"The Matrix", released:1999}}] AS row
MERGE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) ON CREATE SET n += row.properties SET n:Movie;

UNWIND [{_id:7, properties:{born:1967, name:"Carrie-Anne Moss"}},
        {_id:27, properties:{born:1964, name:"Keanu Reeves"}},
        {_id:80, properties:{born:1960, name:"Hugo Weaving"}},
        {_id:44, properties:{born:1961, name:"Laurence Fishburne"}}] AS row
MERGE (n:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row._id}) ON CREATE SET n += row.properties SET n:Person;

UNWIND [{start: {_id:27}, end: {_id:0}, properties:{roles:["Neo"]}},
        {start: {_id:7}, end: {_id:0}, properties:{roles:["Trinity"]}},
        {start: {_id:44}, end: {_id:0}, properties:{roles:["Morpheus"]}},
        {start: {_id:80}, end: {_id:0}, properties:{roles:["Agent Smith"]}}] 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;

In this example we’re using the MERGE clause to create a node if it doesn’t already exist, and are only creating properties if the node doesn’t already exist. In this example, relationships don’t exist in the destination database and need to be created.

If those relationships do exist but have properties that need to be updated, we can use cypherFormat: "updateStructure" to create our import script.

The following exports the ACTED_IN relationships and surrounding nodes to export-cypher-format-updateStructure.cypher using the updateStructure format

MATCH (person)-[r:ACTED_IN]->(movie)
WITH collect(DISTINCT person) + collect(DISTINCT  movie) AS importNodes, collect(r) AS importRels
CALL apoc.export.cypher.data(importNodes, importRels,
  "export-cypher-format-updateStructure.cypher",
  { format: "plain", cypherFormat: "updateStructure" })
YIELD file, batches, source, format, nodes, relationships, properties, time, rows, batchSize
RETURN file, batches, source, format, nodes, relationships, properties, time, rows, batchSize;
Table 5. Results
file batches source format nodes relationships properties time rows batchSize

"export-cypher-format-updateStructure.cypher"

1

"data: nodes(5), rels(4)"

"cypher"

0

4

4

2

4

20000

export-cypher-format-updateStructure.cypher
UNWIND [{start: {_id:27}, end: {_id:0}, properties:{roles:["Neo"]}},
        {start: {_id:7}, end: {_id:0}, properties:{roles:["Trinity"]}},
        {start: {_id:44}, end: {_id:0}, properties:{roles:["Morpheus"]}},
        {start: {_id:80}, end: {_id:0}, properties:{roles:["Agent Smith"]}}] AS row
MATCH (start:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.start._id})
MATCH (end:`UNIQUE IMPORT LABEL`{`UNIQUE IMPORT ID`: row.end._id})
MERGE (start)-[r:ACTED_IN]->(end) SET r += row.properties;