Query D1 from SvelteKit

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 SvelteKit 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 configuration file: 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.

TypeScript

TypeScript

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));
}

TypeScript

// 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 {};

JavaScript

import adapter from "@sveltejs/adapter-cloudflare";

export default {
  kit: {
    adapter: adapter({
      // See below for an explanation of these options
      routes: {
        include: ["/*"],
        exclude: ["<all>"],
      },
    }),
  },
};