The DELETE clause is used to delete graph elements—nodes, relationships orpaths.

Terminal DELETE clauses

A DELETE clause that is not followed by another clause is called a terminal clause. When a cypher query ends with a terminal clause, no results will be returned from the cypher function call. However, the cypher function call still requires a column list definition. When cypher ends with a terminal node, define a single value in the column list definition: no data will be returned in this variable.

Introduction

For removing properties, see REMOVE.

You cannot delete a node without also deleting edges that start or end on said vertex. Either explicitly delete the vertices,or use DETACH DELETE.

Delete isolated vertices

To delete a vertex, use the DELETE clause.

Query

SELECT * 
FROM cypher('graph_name', $$
    MATCH (v:Useless)
    DELETE v
$$) as (v agtype);

This will delete the vertices (with label Useless) that have no edges. Nothing is returned from this query.

Delete all vertices and edges associated with them

Running a MATCH clause will collect all nodes— use the DETACH option to first delete a vertice’s edges, then delete the vertex itself.

Query

SELECT * 
FROM cypher('graph_name', $$
    MATCH (v:Useless)
    DETACH DELETE v
$$) as (v agtype);

Nothing is returned from this query.

Delete edges only

To delete an edge, use the MATCH clause to find your edges, then add the variable to the DELETE clause.

Query

SELECT * 
FROM cypher('graph_name', $$
    MATCH (n {name: 'Andres'})-[r:KNOWS]->()
    DELETE r
$$) as (v agtype);

Nothing is returned from this query.

Return a deleted vertex

You can return vertices that have been deleted with a RETURN clause.

Query

SELECT *
FROM cypher('graph_name', $$
    MATCH (n {name: 'A'})
    DELETE n
    RETURN n
$$) as (a agtype);