CREATE

The CREATE clause is used to create graph vertices and edges.

Terminal CREATE clauses

A CREATE 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.

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE /* Create clause here, no following clause */
$$) as (a agtype);

a

0 row(s) returned

Create single vertex

Creating a single vertex is done by issuing the following query.

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE (n)
$$) as (v agtype);

Nothing is returned from this query.

v

(0 rows)

Create multiple vertices

Creating multiple vertices is done by separating them with a comma.

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE (n), (m)
$$) as (v agtype);

Result

a

0 row(s) returned

Create a vertex with a label

To add a label when creating a vertex, use the following syntax:

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE (:Person)
$$) as (v agtype);

Nothing is returned from this query.

Result

v

0 row(s) returned

Create a vertex with labels and properties

You can create a vertex with labels and properties at the same time.

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE (:Person {name: 'Andres', title: 'Developer'})
$$) as (n agtype);

Nothing is returned from this query.

Result

n

(0 rows)

Return created node

You can create and return a node within the same query as follows:

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE (a {name: 'Andres'})
    RETURN a
$$) as (a agtype);

The newly-created node is returned.

Result

a

{id: 0; label: ‘’; properties: {name: ‘Andres’}}::vertex

(1 row)

Create an edge between two nodes

To create an edge between two vertices, we first MATCH the two vertices. Once the nodes are matched, we create an edge between them.

Query

SELECT * 
FROM cypher('graph_name', $$
    MATCH (a:Person), (b:Person)
    WHERE a.name = 'Node A' AND b.name = 'Node B'
    CREATE (a)-[e:RELTYPE]->(b)
    RETURN e
$$) as (e agtype);

The created edge is returned by the query.

Result

e

{id: 3; startid: 0, endid: 1; label: ‘RELTYPE’; properties: {}}::edge

(1 row)

Create an edge and set properties

Setting properties on edges is done in a similar manner to setting properties when creating vertices. Note that the values can be any expression.

Query

SELECT * 
FROM cypher('graph_name', $$
    MATCH (a:Person), (b:Person)
    WHERE a.name = 'Node A' AND b.name = 'Node B'
    CREATE (a)-[e:RELTYPE {name:a.name + '<->' + b.name}]->(b)
    RETURN e
$$) as (e agtype);

The newly-created edge is returned by the example query.

Result

e

{id: 3; startid: 0, endid: 1; label: ‘RELTYPE’; properties: {name: ‘Node A<->Node B’}}::edge

(1 row)

Create a full path

When you use CREATE and a pattern, all parts of the patterns that are not already in scope at this time will be created.

Query

SELECT * 
FROM cypher('graph_name', $$
    CREATE p = (andres {name:'Andres'})-[:WORKS_AT]->(neo)<-[:WORKS_AT]-(michael {name:'Michael'})
    RETURN p
$$) as (p agtype);

This query creates three nodes and two relationships simultaneously, assigns the pattern to a path variable, and returns said pattern.

Result

p

[{id:0; label: ‘’; properties:{name:’Andres’}}::vertex,
{id: 3; startid: 0, endid: 1; label: ‘WORKS_AT’; properties: {}}::edge,
{id:1; label: ‘’; properties: {}}::vertex,
{id: 3; startid: 2, endid: 1; label: ‘WORKS_AT’; properties: {}}::edge,
{id:2; label: ‘’; properties: {name:’Michael’}}::vertex]::path

(1 row)