SingleStore Data Connector

The Hasura SingleStore Connector ("the connector") enables you to connect to a SingleStore database and gives instant access to a GraphQL API on top of your data.

This connector is built using the Typescript Data Connector SDK and, it implements the Data Connector Spec.

• See the listing in the Hasura Hub
• Hasura V3 Documentation

Features

The following matrix lists the features supported by the Hasura SingleStore connector:

Feature	Supported	Notes
Native Queries + Logical Models	❌
Simple Object Query	✅
Filter / Search	✅
Simple Aggregation	✅
Sort	✅
Paginate	✅
Table Relationships	✅
Views	✅
Distinct	✅
Remote Relationships	✅
Mutations	❌	coming soon

Prerequisites

1. Create a Hasura Cloud account
2. Please ensure you have the DDN CLI and Docker installed
3. Create a supergraph
4. Create a subgraph
5. An active SingleStore deployment that serves as the data source for the API.

The steps below explain how to initialize and configure a connector on your local machine (typically for development purposes).You can learn how to deploy a connector to Hasura DDN — after it's been configured — here.

Using the SingleStore connector

With the context set for an existing subgraph, initialize the connector:

ddn connector init -i

When the wizard runs, you'll be prompted to enter the following env vars necessary for your connector to function:

Name	Default	Description
SINGLESTORE_HOST	localhost	Hostname of the SingleStore database to connect with.
SINGLESTORE_PORT	3306	Port number of the SingleStore database.
SINGLESTORE_USER		SingleStore user to authenticate as.
SINGLESTORE_PASSWORD		Password of the SingleStore database user.
SINGLESTORE_DATABASE		Name of the SingleStore database to connect with.
SINGLESTORE_SSL_CA		CA certificate.
SINGLESTORE_SSL_CERT		Certificate chain in PEM format.
SINGLESTORE_SSL_KEY		Private key in PEM format.
SINGLESTORE_SSL_CIPHERS		Cipher suite specification. If specified, it replaces the default value.
SINGLESTORE_SSL_PASSPHRASE		Shared passphrase used for a single private key.
SINGLESTORE_SSL_REJECT_UNAUTHORIZED	true	If enabled, the server rejects any connection that is not authorized with the list of supplied CAs.

The connector uses MySQL2 library to establish a connection. For more information, refer to Connection options and Pool options.

After the CLI initializes the connector, you'll need to:

• Introspect the source.
• Add your models, commands, and relationships.
• Create a new build.
• Test it by running your project along with the connector.

Note

SingleStore does not support foreign keys. Relationships between tables must be added manually. You can define relationships by appending relationship information to the .hml files generated in the previous step. For information on defining relationships, refer to Relationships. For example, to add a relationship from a message table to the user table, append following text to the DbMessage.hml file:

---
kind: Relationship
version: v1
definition:
  name: user
  sourceType: DbMessage
  target:
    model:
      name: DbUser
      subgraph: app
      relationshipType: Object
  mapping:
    - source:
        fieldPath:
          - fieldName: userId
      target:
        modelField:
          - fieldName: id
  description: The user details for a message

License

The SingleStore connector is available under the Apache License 2.0.