How to delete/create databases in Neo4j?

Question

Is it possible to create/delete different databases in the graph database Neo4j like in MySQL? Or, at least, how to delete all nodes and relationships of an existing graph to get a clean setup for tests, e.g., using shell commands similar to rmrel or rm?

score 100 · Answer 1 · answered Jan 21 '14 at 06:32

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even more simple command to delete all nodes and relationships:

MATCH (n)
OPTIONAL MATCH (n)-[r]-()
DELETE n,r

answered Jan 21 '14 at 06:32

John Bachir

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+1 for the statement. But be aware, just because you delete all the nodes, doesn't mean the labels you used are completely forgotten. The browser will still show all the labels. Ditto for node properties and relationship labels. – Dilum Ranatunga Jun 11 '14 at 19:55
@DilumRanatunga 1. do you know how to make neo forget the labels? 2. how can node properties persist if the nodes are deleted, or relationship labels persiste of the relationships are deleted? – John Bachir Jun 12 '14 at 00:38
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I don't mean the actual values; I mean the property names themselves. – Dilum Ranatunga Jun 12 '14 at 17:46
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there may be not only nodes and edges, but also indexes in the DB, and it's more difficult to get rid of those. also, i just managed to ruin a DB instance by massive repeated testing including deletions and it looks like physically deleting the DB files and having Neo4J recreate them on restart brings a clear improvement in performance. – flow Jul 30 '14 at 14:17
I got out of memory on neo4j in docker container. – bolec_kolec Jul 21 '17 at 08:03
The browser doesn't keep all labels/properties after deletion, it only keeps the ones that have indexes or constraints. to truly reset the DB, you must also delete the indexes/constraints. You can delete them all with an apoc procedure, see https://stackoverflow.com/questions/52593664/how-to-delete-all-indexes-in-neo4j – Cobra Jun 12 '20 at 17:26
Yes, this is a simple and more graceful approach than the previous one mentioned above viz. "rm-rf". – Vikas Pandey Jun 23 '21 at 10:41

score 100 · Accepted Answer · edited Oct 24 '14 at 11:38

100

You can just remove the entire graph directory with rm -rf, because Neo4j is not storing anything outside that:

rm -rf data/*

Also, you can of course iterate through all nodes and delete their relationships and the nodes themselves, but that might be too costly just for testing ...

edited Oct 24 '14 at 11:38

jameshfisher

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answered Dec 22 '10 at 09:32

Peter Neubauer

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And if you iterate over all nodes, it could be a good idea to let the reference node stay. – nawroth Dec 22 '10 at 09:35
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OK, thanks. I already realized this way of erasing all data, but i wasn't sure that this is the 'official' way of doing so... ;-) – rmv Dec 22 '10 at 15:35
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Where's the graph directory located? – Pramod Mar 20 '13 at 16:29
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@Pramod its in the data directory of the neo4j directory. You can't miss it – devshorts Aug 14 '13 at 18:51
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On MacOSX with homebrew: /usr/local/Cellar/neo4j/community-1.9.2-unix/libexec/data – Ashley Sep 10 '13 at 07:27
In C:\Users\USER_NAME\Documents\Neo4j on Windows. – Nadjib Mami Jun 01 '14 at 19:00
@Ashley Thanks, sometimes it's quite a journey to find where a brew installed lib drops stuff! – Ray Jul 19 '14 at 18:44
@Pramod /var/lib/neo4j/data/ on Ubuntu. – Monica Lent Oct 30 '14 at 14:52
Path was changed on Mac: `rm -rf /usr/local/Cellar/neo4j/2.1.7/libexec/data/*` – mre Feb 24 '15 at 16:43
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Perhaps it's a good idea to stop your neo4j server before doing this command. – John Bachir Mar 13 '15 at 16:57
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Users of the Neo4J Web UI take note: **deleting the data directory WILL wipe your command line history!** To safely delete your database while keeping the Web UI commandline history intact, use `rm data/graph.db` – Noah Sussman Aug 18 '15 at 18:59

score 52 · Answer 3 · edited Jun 20 '20 at 09:12

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From Neo4j 2.3,

We can delete all nodes with relationships,

MATCH (n)
DETACH DELETE n

Currently there is no any option to create multiple databases in Noe4j. You need to make multiple stores of Neo4j data. See reference.

edited Jun 20 '20 at 09:12

Community

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answered Oct 28 '15 at 13:07

Somnath Muluk

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Best answer if you don't want to resort to the file system. – ThomasH Aug 03 '17 at 12:53
The problem with this approach is that it won't delete Constraints nor indexes – Davide D'Alto May 21 '18 at 18:06

score 47 · Answer 4 · edited Apr 11 '17 at 13:59

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Creating new Database in Neo4j

Before Starting neo4j community click the browse option

enter image description here

and choose a different directory

enter image description here

and click start button.

enter image description here

New database created on that direcory

edited Apr 11 '17 at 13:59

Cœur

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answered May 29 '14 at 09:53

Bharathiraja

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score 13 · Answer 5 · answered Jul 14 '14 at 20:48

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quick and dirty way that works fine:

bin/neo4j stop
rm -rf data/
mkdir data
bin/neo4j start

answered Jul 14 '14 at 20:48

Scott

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score 11 · Answer 6 · answered Sep 29 '11 at 17:32

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For anyone else who needs a clean graph to run a test suite - https://github.com/jexp/neo4j-clean-remote-db-addon is a great extension to allow clearing the db through a REST call. Obviously, though, don't use it in production!

answered Sep 29 '11 at 17:32

Matt Luongo

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It seems to delete node 0. How do I recreate it? – Will Dec 18 '12 at 20:34
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Actually, it skips the reference node (https://github.com/jexp/neo4j-clean-remote-db-addon/blob/master/src/main/java/org/neo4j/server/extension/test/delete/Neo4jDatabaseCleaner.java#L54). But if your reference node is gone (and you need it) you'll need to start with a clean data dir, since there isn't a `setRefenceNode()` call yet (http://stackoverflow.com/questions/7186832/recreate-reference-node-in-a-neo4j-database). – Matt Luongo Dec 18 '12 at 20:38

score 7 · Answer 7 · edited May 23 '17 at 11:33

Run your test code on a different neo4j instance.

Copy your neo4j directory into a new location. Use this for testing. cd into the new directory.
Change the port so that you can run your tests and use it normally simultaneously. To change the port open conf/neo4j-server.properties and set org.neo4j.server.webserver.port to an unused one.
Start the test server on setup. Do ./neo4j stop and rm -rf data/graph.db on teardown.

For more details see neo4j: How to Switch Database? and the docs.

score 6 · Answer 8 · answered Feb 08 '14 at 03:25

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In Neo4j 2.0.0 the ? is no longer supported. Use OPTIONAL MATCH instead:

START n=node(*)
OPTIONAL MATCH (n)-[r]-()
delete n,r;

answered Feb 08 '14 at 03:25

charles

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score 6 · Answer 9 · answered Jun 11 '15 at 22:19

Easiest answer is: NO

The best way to "start over" is to

move to another empty data folder

or

close Neo4j completely
empty the old data folder
restart Neo4j and set the empty folder as the data folder

There is a way to delete all nodes and relationships (as described here)

MATCH (n)
OPTIONAL MATCH (n)-[r]-()
DELETE n,r

score 2 · Answer 10 · answered Apr 25 '17 at 11:50

As of version 3 I believe it is now possible to create separate database instances and thus their location is slightly different.

Referring to:https://neo4j.com/developer/guide-import-csv/

The --into retail.db is obviously the target database, which must not contain an existing database.

On my Ubuntu box the location is in:

/var/lib/neo4j/data/databases where I currently see only graph.db which I believe must be the default.

score 1 · Answer 11 · answered Nov 14 '13 at 10:02

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In 2.0.0 -M6 You can execute the following Cypher script to delete all nodes and relations:

start n=node(*)
match (n)-[r?]-()
delete n,r

answered Nov 14 '13 at 10:02

Martin Seeler

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Unfortunately this produces an error in the latest 2.0.0 release: SyntaxException: Question mark is no longer used for optional patterns - use OPTIONAL MATCH instead (line 1, column 26) ==> "start n=node(*) match (n)-[r?]-() delete n,r" – richj Jan 30 '14 at 09:43
I don't understand the downvotes, since the answer says clearly *In 2.0.0 -M6*, which was the latest version when I answered the question, while other provided correct answers for the *currently* latest build. – Martin Seeler Feb 14 '14 at 12:08

score 1 · Answer 12 · answered Jul 26 '21 at 17:37

If you have very large database,

`MATCH (n) DETACH DELETE n`

would take lot of time and also database may get stuck(I tried to use it, but does not work for a very large database). So here is how I deleted a larger Neo4j database on a linux server.

First stop the running Neo4j database.

sudo neo4j stop
Second, delete the databases folder and transactions folder inside data folder in neo4j folder. So where to find the neo4j folder? You can find the neo4j executable path by executing which neo4j. Check for data folder going through that path (it is located inside neo4j folder). And go inside the data folder and you will see databases and transactions folders.

rm -rf databases/ rm -rf transactions/
Restart the Neo4j server

sudo neo4j start

score 0 · Answer 13 · answered Oct 07 '15 at 14:57

0

You can delete your data files and if you want to go through this way, I would recommend delete just your graph.db, for example. Otherwise your are going to mess your authentication info.

answered Oct 07 '15 at 14:57

raeffray

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score 0 · Answer 14 · answered Jul 26 '23 at 20:21

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Create a New DB dbms.databases.my_new_database_name=neo4j

Switch B/w Databases USE my_new_database_name

Delete a DB MATCH (n) DETACH DELETE n

answered Jul 26 '23 at 20:21

Mubeen Siddiqui

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How to delete/create databases in Neo4j?

14 Answers14

From Neo4j 2.3,

Linked