@flowblade/source-kysely

A source adapter for Kysely.

Install

yarn add @flowblade/core @flowblade/source-kysely kysely

# Install optional drivers
# 01. for Ms SqlServer or Azure Sql Edge
yarn add tedious tarn

Kysely supports

Quick start

// Your db configuration, see Utils section for more details
import { db } from "@/config/db.config.ts";
import { KyselyDatasource, isQueryResultError } from "@flowblade/source-kysely";
import { sql } from "kysely";

import { KyselyDatasource, isQueryResultError } from "@flowblade/source-kysely";

const ds = new KyselyDatasource({ db });
const query = ds.queryBuilder // This gives access to Kysely expression builder
  .selectFrom("brand as b")
  .select(["b.id", "b.name"])
  .leftJoin("product as p", "p.brand_id", "b.id")
  .select(["p.id as product_id", "p.name as product_name"])
  .where("b.created_at", "<", new Date())
  .orderBy("b.name", "desc");

const result = await ds.query(query);

// Or with query information (will be sent in the metadata)
// const result = await ds.query(query, {
//  name: 'getBrands'
// });

// Option 1: the QResult object contains the data, metadata and error
//  - data:  the result rows (TData or undefined if error)
//  - error: the error (QError or undefined if success)
//  - meta:  the metadata (always present)

const { data, meta, error } = result;

// Option 2: You operate over the result, ie: mapping the data

const { data: data2 } = result.map((row) => {
  return {
    ...data,
    key: `key-${row.productId}`,
  };
});

Streaming

import { KyselyDatasource } from "@flowblade/source-kysely";

const ds = new KyselyDatasource({ db });
const query = ds.queryBuilder // This gives access to Kysely expression builder
  .selectFrom("brand as b")
  .select(["b.id", "b.name"]);

const stream = ds.stream(query, {
  // Chunksize used when reading the database
  // @default undefined
  chunkSize: undefined,
});

for await (const brand of stream) {
  console.log(brand.name);
  if (brand.name === "Something") {
    // Breaking or returning before the stream has ended will release
    // the database connection and invalidate the stream.
    break;
  }
}

Utils

createKyselyMssqlDialect

Create a Kysely dialect for Ms SqlServer or Azure Sql Edge.

import * as Tedious from "tedious";
import {
  TediousConnUtils,
  createKyselyMssqlDialect,
} from "@flowblade/source-kysely";

const jdbcDsn =
  "sqlserver://localhost:1433;database=db;user=sa;password=pwd;trustServerCertificate=true;encrypt=false";
const tediousConfig = TediousConnUtils.fromJdbcDsn(jdbcDsn);

const dialect = createKyselyMssqlDialect({
  tediousConfig,
  // 👉 Optional tarn pool options
  poolOptions: {
    min: 0, // 👉 Minimum number of connections, default 0
    max: 10, // 👉 Maximum number of connections, default 10
    propagateCreateError: true, // 👉 Propagate connection creation errors, default false
  },
  dialectConfig: {
    /**
     * When true, connections are validated before being acquired from the pool,
     * resulting in additional requests to the database.
     *
     * In safe scenarios, this can be set to false to improve performance.
     *
     * Defaults to `true`.
     */
    validateConnections: true,
    /**
     * When true, connections are reset to their initial states when released back to the pool,
     * resulting in additional requests to the database.
     *
     * Defaults to `false`.
     */
    resetConnectionsOnRelease: false,
    // 👉 Override Tedious types to enhance compatibility and modern support
    tediousTypes: {
      ...Tedious.TYPES,
      // see https://github.com/kysely-org/kysely/issues/1161#issuecomment-2384539764
      NVarChar: Tedious.TYPES.VarChar,
      // see https://github.com/kysely-org/kysely/issues/1596#issuecomment-3341591075
      DateTime: Tedious.TYPES.DateTime2,
    },
  },
});

const db = new Kysely<DB>({
  dialect,
});

Note: For performance you can avoid connection roundtrips by setting validateConnections to false and resetConnectionOnRelease to false.

TediousConnUtils

fromJdbcDsn

Parse and validate a JDBC connection string and return a Tedious connection configuration.

import * as Tedious from "tedious";
import { TediousConnUtils } from "@flowblade/source-kysely";

// In your .env file
// DB_JDBC_DSN="sqlserver://localhost:1433;database=db;user=sa;password=pwd;trustServerCertificate=true;encrypt=false";

const tediousConfig = TediousConnUtils.fromJdbcDsn(process.env.DB_JDBC_DSN);

const tediousConnection = new Tedious.Connection(tediousConfig);

Compatibility

| Level | CI | Description | | ------------ | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Node | ✅ | CI for 20.x, 22.x. & 24.x | | Cloudflare | ✅ | Ensured with @cloudflare/vitest-pool-workers (see wrangler.toml | | Browserslist | ✅ | > 95% on 01/2025. Chrome 96+, Firefox 90+, Edge 19+, ios 15+, Safari 15+ and Opera 77+ | | Typescript | ✅ | TS 5.0 + / are-the-type-wrong checks on CI. | | ES2022 | ✅ | Dist files checked with es-check | | Performance | ✅ | Monitored with codspeed.io |

Contributors

Contributions are welcome. Have a look to the CONTRIBUTING document.

Sponsors

Sponsor, coffee, or star – All is spent for quality time with loved ones. Thanks ! 🙏❤️

Special thanks to

License

MIT © Sébastien Vanvelthem and contributors.