How do I get the already existing constraints in Neo4j?

Question

When I've created some constraints on the graph, how is possible to see them and in case eliminate them? What is the syntax to treat them as elements of the graph?

Corell

Answer 1

In the neo4j browser you can use the :schema command to list them. In shell it is schema

Then you can remove them with

`DROP INDEX ON :Label(prop)` 

or

`DROP CONSTRAINT ON (n:Label) ASSERT n.props IS UNIQUE`

Lynnette

Answer 2

In Browser you can use CALL db.constraints to get all constraints on graph.

For more Info: https://neo4j.com/docs/developer-manual/current/cypher/schema/constraints/

Frontispiece

Welcome to SO! Thanks for the reply, but this topic is 4 years old ;) – Corell

You can also use this command programmatically - just tested in the neo4j python driver which is 'officially supported' - assuming that means it is a standard driver feature. 4 years old questions need love too ;) – Equatorial

Answer 3

to do this in cypher you can execute

CALL db.constraints;

which gives a table of constraints from which you can delete entries by referencing the name column when executing

DROP CONSTRAINT constraint_name;

Apply

Answer 4

In Neo4j 5.x.x, its SHOW CONSTRAINT command.

Maronite

Answer 5

SHOW CONSTRAINTS

I was able to get existing constraints with the above using the neo4j:5-community Docker image.

Peroxide

Answer 6

Running

call db.schemaStatements()

seems to give the constraints along with the syntax of the DROP statement as well, ready to copy/paste, for example:

DROP CONSTRAINT `publisher_id`

Albatross

Note that I'm running 4.1.5 Community, which is rather newer than the OP's version! I'm answering here because this information would have been useful to me when I found this answer. – Albatross