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Quick Start

Try Nebula Graph from Docker

The easiest way to get Nebula Graph up and running is using Docker. Before you start, make sure that you have:

  • Installed the latest version of Docker

  • Pulled the latest images of Nebula from Nebula Docker Hub. If not, pull the images using the following command:

> docker pull vesoft/nebula-graph:nightly

Startup Service

When nebula image is ready, run a container:

> docker run -it vesoft/nebula-graph:nightly /bin/bash

After login, you're in the root directory and you should switch to the nebula directory

> cd /usr/local/nebula/

Start meta service, storage service and graph service:

> scripts/nebula.service start all

Check services' status:

> scripts/nebula.service status all

Connect to Service

> bin/nebula -u=user -p=password
  • -u is to set the user name, user is the default Nebula user account
  • -p is to set password, password is the default password for account user

Further more, if you run the console (bin/nebula) in a remote host from graphd, please specify the server's ip and port:

> bin/nebula -u=user -p=password -addr={graphd ip} --port={graphd port}

If you have any questions or concerns about the deployment procedures, please do not hesitate to open an issue on GitHub.

Build Your Own Graph

This section describes how to build a graph and run queries. The example is built on the graph below:

Untitled Diagram (1)

There are three kinds of tags (course, building and student) and two edge types (select and like).

Create a Graph Space

First, we need to create a space and use it before other operations.

To list all existing spaces:

nebula> SHOW SPACES;

To create a new space named myspace_test2:

nebula> CREATE SPACE myspace_test2 (partition_num=1024, replica_factor=1);
-- Use this space
nebula> USE myspace_test2;
  • replica_factor specifies the number of replicas in the cluster.
  • partition_num specifies the number of partitions in one replica.

Define Graph Schema

The CREATE TAG statement defines a tag, with a type name and an attribute list.

nebula> CREATE TAG course (name string, credits int);
nebula> CREATE TAG building (name string);
nebula> CREATE TAG student (name string, age int, gender string);

The CREATE EDGE statement defines an edge type.

nebula> CREATE EDGE like(likeness double);
nebula> CREATE EDGE select(grade int);

To list the tags and edge types that we just created：

-- Show tag list
nebula> SHOW TAGS;
-- Show edge type list
nebula> SHOW EDGES;

To show the attributes of a tag or an edge type:

-- Show attributes of a tag
nebula> DESCRIBE TAG student;
-- Show attributes of an edge type
nebula> DESCRIBE EDGE like;

Insert Data

Insert the vertices and edges based on the graph above.

-- Insert vertices
nebula> INSERT VERTEX student(name, age, gender) VALUES 200:("Monica", 16, "female");
nebula> INSERT VERTEX student(name, age, gender) VALUES 201:("Mike", 18, "male");
nebula> INSERT VERTEX student(name, age, gender) VALUES 202:("Jane", 17, "female");
nebula> INSERT VERTEX course(name, credits),building(name) VALUES 101:("Math", 3, "No5");
nebula> INSERT VERTEX course(name, credits),building(name) VALUES 102:("English", 6, "No11");

-- Insert edges
nebula> INSERT EDGE select(grade) VALUES 200 -> 101:(5);
nebula> INSERT EDGE select(grade) VALUES 200 -> 102:(3);
nebula> INSERT EDGE select(grade) VALUES 201 -> 102:(3);
nebula> INSERT EDGE select(grade) VALUES 202 -> 102:(3);
nebula> INSERT EDGE like(likeness) VALUES 200 -> 201:(92.5);
nebula> INSERT EDGE like(likeness) VALUES 201 -> 200:(85.6);
nebula> INSERT EDGE like(likeness) VALUES 201 -> 202:(93.2);

Sample Queries

Q1. Find the vertexes that 201 likes:

nebula> GO FROM 201 OVER like;
=============
| like._dst |
=============
| 200       |
-------------
| 202       |
-------------

Q2. Find the vertexes that 201 likes, whose ages are greater than 17. Return their name, age and gender, and alias the columns as Friend, Age and Gender, respectively.

nebula> GO FROM 201 OVER like WHERE $$.student.age >= 17 YIELD $$.student.name AS Friend, \
  $$.student.age AS Age, $$.student.gender AS Gender;
=========================
| Friend | Age | Gender |
=========================
|   Jane |  17 | female |
-------------------------

You can use backslash (\) as line break;

  • YIELD specifies what values or results you might want to return from query.
  • $^ represents the source vertex.
  • $$ indicates the target vertex.

Q3. Find the selected courses and corresponding grades of students liked by 201.

-- By pipe
nebula> GO FROM 201 OVER like yield like._dst as id \
  | GO FROM $-.id OVER select YIELD $^.student.name AS Student,\
  $$.course.name AS Course, select.grade AS Grade;
=============================
| Student |  Course | Grade |
=============================
|  Monica |    Math |     5 |
-----------------------------
|  Monica | English |     3 |
-----------------------------
|    Jane | English |     3 |
-----------------------------

-- By temporary variable
nebula> $var=GO FROM 201 OVER like yield like._dst as id; \
  GO FROM $var.id OVER select YIELD $^.student.name AS Student,\
  $$.course.name AS Course, select.grade AS Grade;
=============================
| Student |  Course | Grade |
=============================
|  Monica |    Math |     5 |
-----------------------------
|  Monica | English |     3 |
-----------------------------
|    Jane | English |     3 |
-----------------------------
  • | denotes a pipe. The output of the formal query acts as input to the next one like a pipeline.
  • $- refers to the input stream.

The second approach adopts a user-defined variable $var. The scope of this variable is within the compound statement.