SQL Server Connector

With this connector, Hasura allows you to instantly create a real-time GraphQL API on top of your data models in Microsoft SQL Server. This connector supports SQL Server's functionalities listed in the table below, allowing for efficient and scalable data operations. Additionally, users benefit from all the powerful features of Hasura’s Data Delivery Network (DDN) platform, including query pushdown capabilities that delegate query operations to the database, thereby enhancing query optimization and performance.

This connector is built using the Rust Data Connector SDK and implements the Data Connector Spec.

• Connector information in the Hasura Hub
• Hasura V3 Documentation

Features

Below, you'll find a matrix of all supported features for the SQL Server connector:

Feature	Supported	Notes
Native Queries + Logical Models	✅
Native Mutations	✅
Simple Object Query	✅
Filter / Search	✅
Simple Aggregation	✅
Sort	✅
Paginate	✅
Table Relationships	✅
Views	✅
Remote Relationships	✅
Custom Fields	❌
Mutations	✅	Only native mutations are suppported
Distinct	✅
Enums	❌
Naming Conventions	❌
Default Values	❌
User-defined Functions	❌

Before you get Started

1. Create a Hasura Cloud account
2. Install the CLI
3. Install the Hasura VS Code extension
4. Create a supergraph
5. Create a subgraph

Using the connector

To use the SQL Server connector, follow these steps in a Hasura project: (Note: for more information on the following steps, please refer to the Postgres connector documentation here)

1. Init the connector

(Note: here and following we are naming the subgraph "my_subgraph" and the connector "my_sql")

ddn connector init my_sql --subgraph my_subgraph --hub-connector hasura/sqlserver

2. Add your SQLServer credentials

Add your credentials to my_subgraph/connector/my_sql/.env.local

OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://local.hasura.dev:4317
OTEL_SERVICE_NAME=my_subgraph_my_sql
CONNECTION_URI=<YOUR_SQLSERVER_URL>

3. Introspect your indices

From the root of your project run:

ddn connector introspect --connector my_subgraph/connector/my_sql/connector.yaml

If you look at the configuration.json for your connector, you'll see metadata describing your SQL Server mappings.

4. Create the Hasura metadata

Run the following from the root of your project:

ddn connector-link add my_sql --subgraph my_subgraph

The generated file has two environment variables — one for reads and one for writes — that you'll need to add to your subgraph's .env.my_subgraph file. Each key is prefixed by the subgraph name, an underscore, and the name of the connector. Ensure the port value matches what is published in your connector's docker compose file.

MY_SUBGRAPH_MY_SQL_READ_URL=http://local.hasura.dev:8081
MY_SUBGRAPH_MY_SQL_WRITE_URL=http://local.hasura.dev:8081

5. Start the connector's docker compose

Let's start our connector's docker compose file. Run the following from the connector's subdirectory inside a subgraph:

docker compose -f docker-compose.my_sql.yaml up

This starts our SQL Server connector on the specified port. We can navigate to the following address, with the port modified, to see the schema of our SQL Server data source:

http://localhost:8081/schema

6. Include the connector in your docker compose

Kill the connector by pressing CTRL+C in the terminal tab in which the connector is running.

Then, add the following inclusion to the docker compose docker-compose.hasura.yaml in your project's root directory, taking care to modify the subgraph's name.

include:
  - path: my_subgraph/connector/my_sql/docker-compose.my_sql.yaml

Now, whenever running the following, you'll bring up the GraphQL engine, observability tools, and any connectors you've included. From your project's root directory, run:

HASURA_DDN_PAT=$(ddn auth print-pat) docker compose -f docker-compose.hasura.yaml watch

7. Update the new DataConnectorLink object

Finally, now that our DataConnectorLink has the correct environment variables configured for the SQL Server connector, we can run the update command to have the CLI look at the configuration JSON and transform it to reflect our database's schema in hml format. In a new terminal tab from your project's root directory run:

ddn connector-link update my_sql --subgraph my_subgraph

After this command runs, you can open your my_subgraph/metadata/my_sql.hml file and see your metadata completely scaffolded out for you 🎉

8. Import all your indices

You can do this with just one command. From your project's root directory, run:

ddn connector-link update my_sql --subgraph my_subgraph --add-all-resources

9. Create a supergraph build

Pass the local subcommand along with specifying the output directory as ./engine in the root of the project. This directory is used by the docker-compose file to serve the engine locally. From your project's root directory, run:

ddn supergraph build local --output-dir ./engine

You can now navigate to https://console.hasura.io/local/graphql?url=http://localhost:3000 and interact with your API using the Hasura Console.

Documentation

View the full documentation for the ndc-sqlserver connector here.

Contributing

We're happy to receive any contributions from the community. Please refer to our development guide.

License

The Hasura SQL Server connector is available under the Apache License 2.0.