Release History
Help

YMatrix

Quick Start

Deployment

Data Usage

Manage Clusters

Security

Best Practice

Technical Principles

Advanced Features

Graph Database

Guide

SQL Reference

FAQ

CREATE

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

Note!
In YMatrix AGE, all vertices and edges created by CREATE clauses within a single cypher() function call are placed on the same segment.

Terminal CREATE Clauses

A CREATE clause that is not followed by any other clause is called a terminal clause. When a Cypher query ends with a terminal clause, the cypher() function returns no rows. However, the function call still requires a column definition list — for example, AS (a agtype). When the query ends with a terminal clause, you may define any dummy column name; it will not contain data.

Query

SELECT *
FROM cypher('graph_name', $$
    CREATE /* This is a terminal CREATE clause with no subsequent clauses */
$$) AS (a agtype);

Result

a
Returns 0 rows

Creating a Single Vertex

Use the following query to create a single vertex.

Query

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

This query returns no data.

v
(0 rows)

Creating Multiple Vertices

Separate multiple vertex patterns with commas.

Query

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

Result

a
Returns 0 rows

Creating a Labeled Vertex

Add labels to a vertex using the syntax :Label.

Query

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

This query returns no data.

Result

v
Returns 0 rows

Creating a Labeled Vertex with Properties

You may create a labeled vertex and assign properties in the same CREATE clause.

Query

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

This query returns no data.

Result

n
(0 rows)

Returning Created Nodes

You can both create and return nodes in the same query using RETURN.

Query

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

Returns the newly created node.

Result

a
{id: 0; label: ''; properties: {name: 'Andres'}}::vertex
(1 row)

Creating Self-Loops

To create an edge where the start and end vertices are the same (startid = endid), use either of the following approaches:

  • Create the self-loop directly in CREATE.
  • First MATCH the vertex, then CREATE the edge.

Query (Direct Creation)

SELECT *
FROM cypher('graph_name', $$
    CREATE (a)-[e:RELTYPE]->(a)
    RETURN e
$$) AS (e agtype);

Result

e
{id: 0; startid: 0, endid: 0; label: 'RELTYPE'; properties: {}}::edge
(1 row)

Query (Using MATCH First)

SELECT *
FROM cypher('graph_name', $$
    MATCH (a:Person)
    CREATE (a)-[e:RELTYPE]->(a)
    RETURN e
$$) AS (e agtype);

Result

e
{id: 0; startid: 0, endid: 0; label: 'RELTYPE'; properties: {}}::edge
(1 row)

Creating an Edge Between Two Nodes

To create an edge between two existing vertices, first MATCH both vertices, then CREATE the edge.

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);

Returns the newly created edge.

Result

e
{id: 3; startid: 0, endid: 1; label: 'RELTYPE'; properties: {}}::edge
(1 row)

Creating an Edge with Properties

Edge properties are specified similarly to vertex properties. Property values may be arbitrary expressions.

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);

Returns the newly created edge.

Result

e
{id: 3; startid: 0, endid: 1; label: 'RELTYPE'; properties: {name: 'Node A<->Node B'}}::edge
(1 row)

Creating a Full Path

When CREATE is used with a pattern, all parts of the pattern that do not already exist in the current scope are 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 vertices and two edges, binds the full path to variable p, and returns it.

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)
← Previous
Importing Graph from Files
Next →
MATCH