fastify-kysely

Fastify Kysely connection plugin; with this you can share the same Kysely instances in every part of your server.

Install

npm i kysely fastify-kysely

Usage

Add it to your project with register and you are done!

Typescript

By default fastify-kysely is using generic empty FastifyKyselyNamespaces interfaces, it is possible to set your namespaces with their DBs:

declare module 'fastify' {

    interface FastifyKyselyNamespaces {
        sqliteDB: Kysely<SQLiteDatabase>,
        postgresDB: Kysely<PostgresDatabase>
    }

}

Create a new Kysely instance

Under the hood kysely is used as SQL query builder, the options that you pass to register will be the namespace and Kysely instance.

import fastify from 'fastify'
import Database from 'better-sqlite3'
import { fastifyKysely } from 'fastify-kysely'
import { Generated, Kysely, SqliteDialect } from 'kysely'

interface Database {
    person: PersonTable
}

interface PersonTable {
    id: Generated<number>

    first_name: string

    last_name: string
}

declare module 'fastify' {

    interface FastifyKyselyNamespaces {
        sqliteDB: Kysely<Database>
    }

}


const listen = async (): Promise<void> => {

    const sqliteDialect = new SqliteDialect({
        database: new Database(':memory:')
      })
    
    const kyselyInstance = new Kysely<Database>({dialect: sqliteDialect});

    const server = fastify()

    await server.register(fastifyKysely, {
        namespace: 'sqliteDB',
        kysely: kyselyInstance
    })

    await server.kysely.sqliteDB.schema.createTable('person')
    .addColumn('id', 'integer', (col) => col.primaryKey())
    .addColumn('first_name', 'varchar')
    .addColumn('last_name', 'varchar')
    .execute();
  
    await server.kysely.sqliteDB.insertInto('person')
    .values([
        {
            first_name: 'Max',
            last_name: 'Jack',
        },
        {
            first_name: 'Greg',
            last_name: 'Johnson',
        },
    ])
    .execute();

    server.get('/', async (request, reply) => {
        const result = await request.server.kysely.sqliteDB.selectFrom('person').selectAll().execute()
        return result
    })
    
    server.listen({ port: 5000 }, (err, address) => {
      if (err) {
        console.error(err)
        process.exit(1)
      }
      console.log(`Server listening at ${address}`)
    })
}

listen().then()

Accessing the Kysely instance

Once you have registered your plugin, you can access to Kysely instance via fastify.namespace where namespace is specified in options.

The Kysely instance is automatically destroyed (and connections to db closed) when the fastify instance is closed.

server.register(fastifyKysely, { namespace: 'sqliteDB', kysely: kyselyInstance })

Registering multiple Kysely instances

By using the namespace option you can register multiple Kysely instances.

Compatibility to Fastify Versions

Fastify	fastify-kysely
v4	1.x.x
v5	2.x.x

Example

Example is available here.

License

Licensed under MIT.