duckdbExample

@yawnxyz

Forked from tmcw/duckdbExample

Public

Script

Fork

0 Likes

Readme

DuckDB

DuckDB works on Val Town, with only one small tweak! We're basically using DuckDB in the same way you'd use it with a browser - using the WASM package with its dependencies fetched from jsdelivr.

The only trick is to create the worker ourselves rather than using duckdb.createWorker. DuckDB's built-in createWorker method doesn't specify a worker type, which causes type to default to classic, and Deno (our runtime) doesn't support classic workers.

Note: A small check was added to make this compatible with local Deno.

  if (typeof Deno !== "undefined") {
    return new Worker(url, { type: "module", deno: true });
  }

duckdbExample

import { fetch } from "https://esm.town/v/std/fetch";

export let duckdbExample = await (async () => {

async function createWorker(url) {

// For Val Town / Deno environments

if (typeof Deno !== "undefined") {

return new Worker(url, { type: "module", deno: true });

}

// For browser environments (keeping the original logic)

const workerScript = await fetch(url);

const workerURL = URL.createObjectURL(await workerScript.blob());

return new Worker(workerURL, { type: "module" });

}

const duckdb = await import(

"https://cdn.jsdelivr.net/npm/@duckdb/duckdb-wasm@1.17.0/+esm"

);

const bundles = duckdb.getJsDelivrBundles();

const bundle = await duckdb.selectBundle(bundles);

const logger = new duckdb.ConsoleLogger();

const worker = await createWorker(bundle.mainWorker);

const db = new duckdb.AsyncDuckDB(logger, worker);

await db.instantiate(bundle.mainModule);

const c = await db.connect();

const res = await c.query(`SELECT * FROM generate_series(1, 100) t(v)`);

c.close();

db.terminate();

// DuckDB's toJSON unfortunately includes BigInts, and we can't serialize

// BigInts because they have no basic JSON representation. So,

// Translate them to ints.

return res.toArray().map((r) => {

const row = r.toJSON();

return JSON.parse(JSON.stringify(row, (k, v) => {

return typeof v === "bigint" ? +v.toString() : v;

}));

});

})();

console.log(duckdbExample);

Val Town is a social website to write and deploy JavaScript.

Build APIs and schedule functions from your browser.

Comments

Nobody has commented on this val yet: be the first!

September 2, 2024