Kysely Query Builder Setup

SQLocal provides a dialect for the Kysely query builder so that you can use it to make fully typed queries against databases in your TypeScript codebase.

Install

Install the Kysely package alongside SQLocal in your application using your package manager.

npm

npm install sqlocal kysely

yarn

yarn add sqlocal kysely

pnpm

pnpm install sqlocal kysely

Initialize

SQLocal provides the Kysely dialect from a child class of SQLocal called SQLocalKysely imported from sqlocal/kysely. This class has all the same methods as SQLocal and adds dialect which you pass to the Kysely instance.

import { SQLocalKysely } from 'sqlocal/kysely';
import { Kysely } from 'kysely';

const { dialect } = new SQLocalKysely('database.sqlite3');
export const db = new Kysely({ dialect });

Now, any queries you run through this Kysely instance will be executed against the database passed to SQLocalKysely.

Define Schema

With Kysely, your schema is defined using TypeScript object types. See the Kysely documentation.

import type { Generated } from 'kysely';

export type Database = {
	groceries: GroceriesTable;
};

export type GroceriesTable = {
	id: Generated<number>;
	name: string;
	quantity: number;
};

With this defined, pass the database type to the Kysely instance, and your queries built with Kysely will now have auto-complete and type checking.

export const db = new Kysely<Database>({ dialect });

Make Queries

Import your Kysely instance to start making type-safe queries.

const data = await db
	.selectFrom('groceries')
	.select(['name', 'quantity'])
	.orderBy('name', 'asc')
	.execute();
console.log(data);

See the Kysely documentation for more examples.