export_util

Module for exporting a graph database or query results in different formats. Currently, this module supports exporting database to a JSON file format and exporting query results in a CSV file format.

Trait	Value
Module type	util
Implementation	Python
Parallelism	sequential

Procedures

info

If you want to execute this algorithm on graph projections, subgraphs or portions of the graph, be sure to check out the guide on How to run a MAGE module on subgraphs.

json(path)

Input:

• path: string ➡ Path to the JSON file containing the exported graph database.

Usage:

The path you have to provide as procedure argument depends on how you started Memgraph.

Docker

If you ran Memgraph with Docker, database will be exported to a JSON file inside the Docker container. We recommend exporting the database to the JSON file inside the /usr/lib/memgraph/query_modules directory.

You can call the procedure by running the following query:

CALL export_util.json(path);

where path is the path to the JSON file inside the /usr/lib/memgraph/query_modules directory in the running Docker container (e.g., /usr/lib/memgraph/query_modules/export.json).

info

You can copy the exported CSV file to your local file system using the docker cp command.

Linux

To export database to a local JSON file create a new directory (for example, export_folder) and run the following command to give the user memgraph the necessary permissions:

sudo chown memgraph export_folder

Then, call the procedure by running the following query:

CALL export_util.json(path);

where path is the path to a local JSON file that will be created inside the export_folder (e.g., /users/my_user/export_folder/export.json).

csv_query(query, file_path, stream)

Input:

• query: string ➡ A query from which the results will be saved to a CSV file.
• file_path: string (default="") ➡ A path to the CSV file where the query results will be exported. Defaults to an empty string.
• stream: bool (default=False) ➡ A value which determines whether a stream of query results in a CSV format will be returned.

Output:

• file_path: string ➡ A path to the CSV file where the query results are exported. If file_path is not provided, the output will be an empty string.
• data: string ➡ A stream of query results in a CSV format.

Usage:

The file_path you have to provide as procedure argument depends on how you started Memgraph.

Docker

If you ran Memgraph with Docker, query results will be exported to a CSV file inside the Docker container. We recommend exporting the database to the CSV file inside the /usr/lib/memgraph/query_modules directory.

You can call the procedure by running the following query:

CALL export_util.csv_query(path);

where path is the path to a CSV file inside the /usr/lib/memgraph/query_modules directory in the running Docker container (e.g., /usr/lib/memgraph/query_modules/export.csv).

info

You can copy the exported CSV file to your local file system using the docker cp command.

Linux

To export query results to a local CSV file create a new directory (for example, export_folder) and run the following command to give the user memgraph the necessary permissions:

sudo chown memgraph export_folder

Then, call the procedure by running the following query:

CALL export_util.csv_query(path);

where path is the path to a local CSV file that will be created inside the export_folder (e.g., /users/my_user/export_folder/export.csv).

Example - Exporting database to a JSON file

Step 1: Cypher load commands

You can create a simple graph database by running the following queries:

CREATE (n:Person {name:"Anna"}), (m:Person {name:"John"}), (k:Person {name:"Kim"})
CREATE (n)-[:IS_FRIENDS_WITH]->(m), (n)-[:IS_FRIENDS_WITH]->(k), (m)-[:IS_MARRIED_TO]->(k);

Step 2: Input graph

The image below shows the above data as a graph:

Step 3: Running command

If you're using Memgraph with Docker, the following Cypher query will export the database to the export.json file in the /usr/lib/memgraph/query_modules directory inside the running Docker container.

CALL export_util.json("/usr/lib/memgraph/query_modules/export.json");

If you're using Memgraph on Ubuntu, Debian, RPM package or WSL, the following Cypher query will export the database to the export.json file in the /users/my_user/export_folder.

CALL export_util.json("/users/my_user/export_folder/export.json");

Step 4: Results

The export.json file should be similar to the one below, except for the id values that depend on the internal database id values:

[
    {
        "id": 6114,
        "labels": [
            "Person"
        ],
        "properties": {
            "name": "Anna"
        },
        "type": "node"
    },
    {
        "id": 6115,
        "labels": [
            "Person"
        ],
        "properties": {
            "name": "John"
        },
        "type": "node"
    },
    {
        "id": 6116,
        "labels": [
            "Person"
        ],
        "properties": {
            "name": "Kim"
        },
        "type": "node"
    },
    {
        "end": 6115,
        "id": 21120,
        "label": "IS_FRIENDS_WITH",
        "properties": {},
        "start": 6114,
        "type": "relationship"
    },
    {
        "end": 6116,
        "id": 21121,
        "label": "IS_FRIENDS_WITH",
        "properties": {},
        "start": 6114,
        "type": "relationship"
    },
    {
        "end": 6116,
        "id": 21122,
        "label": "IS_MARRIED_TO",
        "properties": {},
        "start": 6115,
        "type": "relationship"
    }
]

Example - Exporting query results to a CSV file

Step 1: Cypher load commands

You can create a simple graph database by running the following queries:

CREATE (StrangerThings:TVShow {title:'Stranger Things', released:2016, program_creators:['Matt Duffer', 'Ross Duffer']})
CREATE (Eleven:Character {name:'Eleven', portrayed_by:'Millie Bobby Brown'})
CREATE (JoyceByers:Character {name:'Joyce Byers', portrayed_by:'Millie Bobby Brown'})
CREATE (JimHopper:Character {name:'Jim Hopper', portrayed_by:'Millie Bobby Brown'})
CREATE (MikeWheeler:Character {name:'Mike Wheeler', portrayed_by:'Finn Wolfhard'})
CREATE (DustinHenderson:Character {name:'Dustin Henderson', portrayed_by:'Gaten Matarazzo'})
CREATE (LucasSinclair:Character {name:'Lucas Sinclair', portrayed_by:'Caleb McLaughlin'})
CREATE (NancyWheeler:Character {name:'Nancy Wheeler', portrayed_by:'Natalia Dyer'})
CREATE (JonathanByers:Character {name:'Jonathan Byers', portrayed_by:'Charlie Heaton'})
CREATE (WillByers:Character {name:'Will Byers', portrayed_by:'Noah Schnapp'})
CREATE (SteveHarrington:Character {name:'Steve Harrington', portrayed_by:'Joe Keery'})
CREATE (MaxMayfield:Character {name:'Max Mayfield', portrayed_by:'Sadie Sink'})
CREATE (RobinBuckley:Character {name:'Robin Buckley', portrayed_by:'Maya Hawke'})
CREATE (EricaSinclair:Character {name:'Erica Sinclair', portrayed_by:'Priah Ferguson'})
CREATE
(Eleven)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(JoyceByers)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(JimHopper)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(MikeWheeler)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(DustinHenderson)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(LucasSinclair)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(NancyWheeler)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(JonathanByers)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(WillByers)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(SteveHarrington)-[:ACTED_IN {seasons:[1, 2, 3, 4]}]->(StrangerThings),
(MaxMayfield)-[:ACTED_IN {seasons:[2, 3, 4]}]->(StrangerThings),
(RobinBuckley)-[:ACTED_IN {seasons:[3, 4]}]->(StrangerThings),
(EricaSinclair)-[:ACTED_IN {seasons:[2, 3, 4]}]->(StrangerThings);

Step 2: Input graph

The image below shows the above data as a graph:

Step 3: Running command

If you're using Memgraph with Docker, the following Cypher query will export the database to the export.csv file in the /usr/lib/memgraph/query_modules directory inside the running Docker container.

WITH "MATCH path = (c:Character)-[:ACTED_IN]->(tvshow) RETURN c.name AS name, c.portrayed_by AS portrayed_by, tvshow.title AS title, tvshow.released AS released, tvshow.program_creators AS program_creators" AS query
CALL export_util.csv_query(query, "/usr/lib/memgraph/query_modules/export.csv", True)
YIELD file_path, data
RETURN file_path, data;

If you're using Memgraph on Ubuntu, Debian, RPM package or WSL, then the following Cypher query will export the database to the export.csv file in the /users/my_user/export_folder.

WITH "MATCH path = (c:Character)-[:ACTED_IN]->(tvshow) RETURN c.name AS name, c.portrayed_by AS portrayed_by, tvshow.title AS title, tvshow.released AS released, tvshow.program_creators AS program_creators" AS query
CALL export_util.csv_query(query, "/users/my_user/export_folder/export.csv", True)
YIELD file_path, data
RETURN file_path, data;

Step 4: Results

The output in the export.csv file looks like this:

name,portrayed_by,title,released,program_creators
Eleven,Millie Bobby Brown,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Joyce Byers,Millie Bobby Brown,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Jim Hopper,Millie Bobby Brown,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Mike Wheeler,Finn Wolfhard,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Dustin Henderson,Gaten Matarazzo,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Lucas Sinclair,Caleb McLaughlin,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Nancy Wheeler,Natalia Dyer,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Jonathan Byers,Charlie Heaton,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Will Byers,Noah Schnapp,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Steve Harrington,Joe Keery,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Max Mayfield,Sadie Sink,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Robin Buckley,Maya Hawke,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"
Erica Sinclair,Priah Ferguson,Stranger Things,2016,"['Matt Duffer', 'Ross Duffer']"