Databricks

The project includes a reference integration that connects GraphQL queries to a Databricks SQL Warehouse.

Configuration

Add the following variables to your .env.local file:

DATABRICKS_WORKSPACE_URL=https://<workspace>.cloud.databricks.com
DATABRICKS_HTTP_PATH=/sql/1.0/warehouses/your-warehouse-id-here
DATABRICKS_ACCESS_TOKEN=your-databricks-access-token-here

To find these values:

• Workspace URL — The URL you use to access your Databricks workspace (e.g., https://mycompany.cloud.databricks.com).
• HTTP Path — In the Databricks UI, go to SQL Warehouses → Select your warehouse → Connection details → HTTP Path.
• Access Token — Generate a personal access token under Settings → Developer → Access tokens in your Databricks workspace.

Architecture

Databricks queries flow through the existing GraphQL API:

React Component → GraphQL Client → Apollo Server (/api/graphql) → Databricks SQL Warehouse

Key files:

File	Purpose
app/api/graphql/databricks/databricksClient.ts	Singleton DBSQLClient that connects to the warehouse using the env variables above
app/api/graphql/databricks/schema.ts	GraphQL type definitions for Databricks queries
app/api/graphql/databricks/resolvers.ts	Resolver that executes SQL statements against Databricks and maps results
app/databricks/graphqlClient.ts	Client-side GraphQL query definitions used by React components
app/databricks/Databricks.tsx	React component that fetches and displays data in a DaikinTable

Adding a New Databricks Query

1. Browse your catalog — Open your Databricks workspace, click Catalog in the sidebar, and navigate the hierarchy (Catalog → Schema → Table) to identify the table and columns you need.

2. Define the GraphQL schema — Add a new type and query to app/api/graphql/databricks/schema.ts (or create a separate schema file and merge it in app/api/graphql/route.ts).

3. Write the resolver — In app/api/graphql/databricks/resolvers.ts, add a resolver that calls executeQuery() with your SQL statement. The helper accepts named parameters:

   const query = `SELECT col1, col2 FROM my_catalog.my_schema.my_table LIMIT :rowsPerPage`;
   const results = await executeQuery(query, { rowsPerPage: 10 });

4. Create the client query — Add a GraphQL query definition in app/databricks/graphqlClient.ts and export a function that returns a React Query config object (queryKey + queryFn).

5. Build the UI — Create or extend a component under app/databricks/ that calls the query with useQuery() and renders the results.

How the Client Works

The Databricks client (databricksClient.ts) is a singleton that reuses a single DBSQLClient connection. Each query opens a new session, executes the statement, and closes the session. Named parameters are passed via the namedParameters option to prevent SQL injection.