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Get Started with Waddler and CockroachDB

This guide assumes familiarity with:
  • dotenv - package for managing environment variables - read here
  • tsx - package for running TypeScript files - read here
  • node-postgres - package for querying your CockroachDB database - read here

Waddler has native support for CockroachDB connections with the node-postgres driver.

Basic file structure

This is the basic file structure of the project.

📦 <project root>
 ├ 📂 src
 │   └ 📜 index.ts
 ├ 📜 .env
 ├ 📜 package.json
 └ 📜 tsconfig.json

Step 1 - Install node-postgres package

npm
yarn
pnpm
bun 
npm i waddler pg dotenv
npm i -D tsx @types/pg

Step 2 - Setup connection variables

Create a .env file in the root of your project and add your database connection variable:

DATABASE_URL=

Step 3 - Connect Waddler to the database

cockroach
cockroach with config
your node-postgres driver
pg-query-stream extension
import 'dotenv/config';
import { waddler } from 'waddler/cockroach';

const sql = waddler(process.env.DATABASE_URL!);

Step 4 - Create a table


(async () => {
  await sql.unsafe(`create table users (
    id serial primary key,
    name string not null,
    age int4 not null,
    email string not null unique
);
  `);
})()

Step 5 - Seed and Query the database

Let’s update the src/index.ts file with queries to create, read, update, and delete users

src/index.ts
import 'dotenv/config';
import { waddler } from 'waddler/cockroach';
  
const sql = waddler(process.env.DATABASE_URL!);

async function main() {
  const user = [
    'John',
    30,
    'john@example.com',
  ];

  await sql`insert into ${sql.identifier('users')} values ${sql.values([[sql.default, ...user]])};`;
  console.log('New user created!')

  const users = await sql`select * from ${sql.identifier('users')};`;
  console.log('Getting all users from the database: ', users)
  /*
  const users: {
    id: number;
    name: string;
    age: number;
    email: string;
  }[]
  */

  await sql`update ${sql.identifier('users')} set age = ${31} where email = ${user[2]};`;
  console.log('User info updated!')

  await sql`delete from ${sql.identifier('users')} where email = ${user[2]};`;
  console.log('User deleted!')
}

main();

Streaming

src/index.ts
import 'dotenv/config';
import pg from 'pg';
import { waddler } from 'waddler/cockroach';
import { queryStream } from 'waddler/extensions/pg-query-stream';

const { Client } = pg;

async function main() {
  const client = new Client(process.env.DATABASE_URL!);
	await client.connect();

	const sql = waddler({ client, extensions: [queryStream()] });

	const stream = sql`select * from users;`.stream();

	console.log('Streaming users one at a time from the database.')
    for await (const user of stream) {
        console.log(user)
        /*
        const user: {
          id: number;
          name: string;
          age: number;
          email: string;
        }
        */		
	}

	await client.end();
}

main();

Step 6 - Run index.ts file

To run any TypeScript files, you have several options, but let’s stick with one: using tsx

You’ve already installed tsx, so we can run our queries now

Run index.ts script

npm
yarn
pnpm
bun 
npx tsx src/index.ts
tips

We suggest using bun to run TypeScript files. With bun, such scripts can be executed without issues or additional settings, regardless of whether your project is configured with CommonJS (CJS), ECMAScript Modules (ESM), or any other module format. To run a script with bun, use the following command:

bun src/index.ts

If you don’t have bun installed, check the Bun installation docs