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Query D1 from SvelteKit

Query a D1 database from a SvelteKit application.

SvelteKit is a full-stack framework that combines the Svelte front-end framework with Vite for server-side capabilities and rendering. You can query D1 from SvelteKit by configuring a server endpoint with a binding to your D1 database(s).

To set up a new SvelteKit site on Cloudflare Pages that can query D1:

  1. Refer to the Svelte guide and Svelte's Cloudflare adapter.
  2. Install the Cloudflare adapter within your SvelteKit project: npm i -D @sveltejs/adapter-cloudflare.
  3. Bind a D1 database to your Pages Function.
  4. Pass the --d1 BINDING_NAME=DATABASE_ID flag to wrangler dev when developing locally. BINDING_NAME should match what call in your code, and DATABASE_ID should match the database_id defined in your wrangler.toml: for example, --d1 DB=xxxx-xxxx-xxxx-xxxx-xxxx.

The following example shows you how to create a server endpoint configured to query D1.

  • Bindings are available on the platform parameter passed to each endpoint, via platform.env.BINDING_NAME.
  • With SvelteKit's file-based routing, the server endpoint defined in src/routes/api/users/+server.ts is available at /api/users within your SvelteKit app.

The example also shows you how to configure both your app-wide types within src/app.d.ts to recognize your D1Database binding, import the @sveltejs/adapter-cloudflare adapter into svelte.config.js, and configure it to apply to all of your routes.

import type { RequestHandler } from "@sveltejs/kit";
/** @type {import('@sveltejs/kit').RequestHandler} */
export async function GET({ request, platform }) {
let result = await platform.env.DB.prepare(
"SELECT * FROM users LIMIT 5"
).run();
return new Response(JSON.stringify(result));
}
// See https://kit.svelte.dev/docs/types#app
// for information about these interfaces
declare global {
namespace App {
// interface Error {}
// interface Locals {}
// interface PageData {}
interface Platform {
env: {
DB: D1Database;
};
context: {
waitUntil(promise: Promise<any>): void;
};
caches: CacheStorage & { default: Cache };
}
}
}
export {};
import adapter from '@sveltejs/adapter-cloudflare';
export default {
kit: {
adapter: adapter({
// See below for an explanation of these options
routes: {
include: ['/*'],
exclude: ['<all>']
}
})
}
};