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?	{}

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"`
ifNotExists	boolean	false	If true adds the keyword `IF NOT EXISTS` to constraints and indexes

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?

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:

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".

More documentation of apoc.export.cypher.query