# [knex.js](https://knex.github.io/documentation/) [![npm version](http://img.shields.io/npm/v/knex.svg)](https://npmjs.org/package/knex) [![npm downloads](https://img.shields.io/npm/dm/knex.svg)](https://npmjs.org/package/knex) ![](https://github.com/knex/knex/workflows/CI/badge.svg) [![Coverage Status](https://coveralls.io/repos/knex/knex/badge.svg?branch=master)](https://coveralls.io/r/knex/knex?branch=master) [![Dependencies Status](https://img.shields.io/librariesio/github/knex/knex)](https://libraries.io/npm/knex) [![Gitter chat](https://badges.gitter.im/tgriesser/knex.svg)](https://gitter.im/tgriesser/knex) > **A SQL query builder that is _flexible_, _portable_, and _fun_ to use!** A batteries-included, multi-dialect (PostgreSQL, MySQL, CockroachDB, MSSQL, SQLite3, Oracle (including Oracle Wallet Authentication)) query builder for Node.js, featuring: - [transactions](https://knex.github.io/documentation/#Transactions) - [connection pooling](https://knex.github.io/documentation/#Installation-pooling) - [streaming queries](https://knex.github.io/documentation/#Interfaces-Streams) - both a [promise](https://knex.github.io/documentation/#Interfaces-Promises) and [callback](https://knex.github.io/documentation/#Interfaces-Callbacks) API - a [thorough test suite](https://github.com/knex/knex/actions) Node.js versions 12+ are supported. - Take a look at the [full documentation](https://knex.github.io/documentation) to get started! - Browse the [list of plugins and tools](https://github.com/knex/knex/blob/master/ECOSYSTEM.md) built for knex - Check out our [recipes wiki](https://github.com/knex/knex/wiki/Recipes) to search for solutions to some specific problems - In case of upgrading from an older version, see [migration guide](https://github.com/knex/knex/blob/master/UPGRADING.md) You can report bugs and discuss features on the [GitHub issues page](https://github.com/knex/knex/issues) or send tweets to [@kibertoad](http://twitter.com/kibertoad). For support and questions, join our [Gitter channel](https://gitter.im/tgriesser/knex). For knex-based Object Relational Mapper, see: - https://github.com/Vincit/objection.js - https://github.com/mikro-orm/mikro-orm - https://bookshelfjs.org To see the SQL that Knex will generate for a given query, you can use [Knex Query Lab](https://michaelavila.com/knex-querylab/) ## Examples We have several examples [on the website](http://knexjs.org). Here is the first one to get you started: ```js const knex = require('knex')({ client: 'sqlite3', connection: { filename: './data.db', }, }); try { // Create a table await knex.schema .createTable('users', (table) => { table.increments('id'); table.string('user_name'); }) // ...and another .createTable('accounts', (table) => { table.increments('id'); table.string('account_name'); table.integer('user_id').unsigned().references('users.id'); }); // Then query the table... const insertedRows = await knex('users').insert({ user_name: 'Tim' }); // ...and using the insert id, insert into the other table. await knex('accounts').insert({ account_name: 'knex', user_id: insertedRows[0], }); // Query both of the rows. const selectedRows = await knex('users') .join('accounts', 'users.id', 'accounts.user_id') .select('users.user_name as user', 'accounts.account_name as account'); // map over the results const enrichedRows = selectedRows.map((row) => ({ ...row, active: true })); // Finally, add a catch statement } catch (e) { console.error(e); } ``` ## TypeScript example ```ts import { Knex, knex } from 'knex'; interface User { id: number; age: number; name: string; active: boolean; departmentId: number; } const config: Knex.Config = { client: 'sqlite3', connection: { filename: './data.db', }, }; const knexInstance = knex(config); try { const users = await knex('users').select('id', 'age'); } catch (err) { // error handling } ``` ## Usage as ESM module If you are launching your Node application with `--experimental-modules`, `knex.mjs` should be picked up automatically and named ESM import should work out-of-the-box. Otherwise, if you want to use named imports, you'll have to import knex like this: ```js import { knex } from 'knex/knex.mjs'; ``` You can also just do the default import: ```js import knex from 'knex'; ``` If you are not using TypeScript and would like the IntelliSense of your IDE to work correctly, it is recommended to set the type explicitly: ```js /** * @type {Knex} */ const database = knex({ client: 'mysql', connection: { host: '127.0.0.1', user: 'your_database_user', password: 'your_database_password', database: 'myapp_test', }, }); database.migrate.latest(); ```