PostgreSQL に接続する

# wrangler v3.11 and above required
npx wrangler hyperdrive create my-first-hyperdrive --connection-string="postgres://user:password@database.host.example.com:5432/databasenamehere"

// filepath: src/index.ts
import { Client } from "pg";

export default {
	async fetch(
		request: Request,
		env: Env,
		ctx: ExecutionContext,
	): Promise<Response> {
		// Create a new client instance for each request. Hyperdrive maintains the
		// underlying database connection pool, so creating a new client is fast.
		const client = new Client({
			connectionString: env.HYPERDRIVE.connectionString,
		});

		try {
			// Connect to the database
			await client.connect();

			// Perform a simple query
			const result = await client.query("SELECT * FROM pg_tables");

			return Response.json({
				success: true,
				result: result.rows,
			});
		} catch (error: any) {
			console.error("Database error:", error.message);

			return new Response("Internal error occurred", { status: 500 });
		}
	},
};

// filepath: src/index.ts
import postgres from "postgres";

export default {
	async fetch(
		request: Request,
		env: Env,
		ctx: ExecutionContext,
	): Promise<Response> {
		// Create a database client that connects to your database via Hyperdrive.
		// Hyperdrive maintains the underlying database connection pool,
		// so creating a new client on each request is fast and recommended.
		const sql = postgres(env.HYPERDRIVE.connectionString, {
			// Limit the connections for the Worker request to 5 due to Workers' limits on concurrent external connections
			max: 5,
			// If you are not using array types in your Postgres schema, disable `fetch_types` to avoid an additional round-trip (unnecessary latency)
			fetch_types: false,

			// This is set to true by default, but certain query generators such as Kysely or queries using sql.unsafe() will set this to false. Hyperdrive will not cache prepared statements when this option is set to false and will require additional round-trips.  
			prepare: true,
		});

		try {
			// A very simple test query
			const result = await sql`select * from pg_tables`;

			// Return result rows as JSON
			return Response.json({ success: true, result: result });
		} catch (e: any) {
			console.error("Database error:", e.message);

			return Response.error();
		}
	},
} satisfies ExportedHandler<Env>;