base on A query builder for PostgreSQL, MySQL, CockroachDB, SQL Server, SQLite3 and Oracle, designed to be flexible, portable, and fun to use. # [knex.js](https://knex.github.io/documentation/) [](https://npmjs.org/package/knex) [](https://npmjs.org/package/knex)  [](https://coveralls.io/r/knex/knex?branch=master) [](https://libraries.io/npm/knex) [](https://gitter.im/tgriesser/knex) > **A SQL query builder that is _flexible_, _portable_, and _fun_ to use!** A batteries-included, multi-dialect (PostgreSQL, MariaDB, MySQL, CockroachDB, MSSQL, SQLite3, Oracle (including Oracle Wallet Authentication)) query builder for Node.js, featuring: - [transactions](https://knexjs.org/guide/transactions.html) - [connection pooling](https://knexjs.org/guide/#pool) - [streaming queries](https://knexjs.org/guide/interfaces.html#streams) - both a [promise](https://knexjs.org/#Interfaces-Promises) and [callback](https://knexjs.org/guide/interfaces.html#callbacks) API - a [thorough test suite](https://github.com/knex/knex/actions) Node.js versions 16+ are supported. - Take a look at the [full documentation](https://knexjs.org/) 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', }, useNullAsDefault: true, }; const knexInstance = knex(config); knexInstance<User>('users') .select() .then((users) => { console.log(users); }) .catch((err) => { console.error(err); }) .finally(() => { knexInstance.destroy(); }); ``` ## 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(); ``` ", Assign "at most 3 tags" to the expected json: {"id":"1337","tags":[]} "only from the tags list I provide: [{"id":39,"name":"3d-generation","display_name":"3D generation","slug":"3d-generation"},{"id":3,"name":"ai-agent","display_name":"AI agent","slug":"ai-agent"},{"id":8,"name":"ai-coding","display_name":"AI coding assistant","slug":"ai-coding"},{"id":5,"name":"ai-image","display_name":"AI image generation","slug":"ai-image"},{"id":9,"name":"ai-infrastructure","display_name":"AI infrastructure","slug":"ai-infrastructure"},{"id":10,"name":"ai-memory","display_name":"AI memory","slug":"ai-memory"},{"id":11,"name":"ai-skills","display_name":"AI skills","slug":"ai-skills"},{"id":12,"name":"ai-translation","display_name":"AI translation","slug":"ai-translation"},{"id":6,"name":"ai-video","display_name":"AI video generation","slug":"ai-video"},{"id":4,"name":"ai-voice","display_name":"AI voice","slug":"ai-voice"},{"id":7,"name":"ai-workflow","display_name":"AI workflow","slug":"ai-workflow"},{"id":22,"name":"audio-processing","display_name":"Audio processing","slug":"audio-processing"},{"id":29,"name":"authentication","display_name":"Authentication","slug":"authentication"},{"id":51,"name":"bundler","display_name":"Bundler","slug":"bundler"},{"id":41,"name":"chatbot","display_name":"Chatbot","slug":"chatbot"},{"id":27,"name":"cloud-native","display_name":"Cloud native","slug":"cloud-native"},{"id":1,"name":"computer-vision","display_name":"Computer vision","slug":"computer-vision"},{"id":37,"name":"crypto-trading","display_name":"Crypto trading","slug":"crypto-trading"},{"id":57,"name":"curated-list","display_name":"Curated list","slug":"curated-list"},{"id":54,"name":"data-streaming","display_name":"Data streaming","slug":"data-streaming"},{"id":35,"name":"data-visualization","display_name":"Data visualization","slug":"data-visualization"},{"id":16,"name":"database-backup","display_name":"Database backup","slug":"database-backup"},{"id":49,"name":"design-system","display_name":"Design system","slug":"design-system"},{"id":38,"name":"digital-human","display_name":"Digital human","slug":"digital-human"},{"id":34,"name":"document-processing","display_name":"Document processing","slug":"document-processing"},{"id":44,"name":"ecommerce","display_name":"E-commerce","slug":"ecommerce"},{"id":45,"name":"emulator","display_name":"Emulator","slug":"emulator"},{"id":46,"name":"file-management","display_name":"File management","slug":"file-management"},{"id":32,"name":"fintech","display_name":"Fintech","slug":"fintech"},{"id":31,"name":"game-development","display_name":"Game development","slug":"game-development"},{"id":24,"name":"headless-browser","display_name":"Headless browser","slug":"headless-browser"},{"id":52,"name":"headless-cms","display_name":"Headless CMS","slug":"headless-cms"},{"id":36,"name":"home-automation","display_name":"Home automation","slug":"home-automation"},{"id":20,"name":"image-editing","display_name":"Image editing","slug":"image-editing"},{"id":28,"name":"iot","display_name":"IoT","slug":"iot"},{"id":13,"name":"local-llm","display_name":"Local LLM","slug":"local-llm"},{"id":17,"name":"mcp","display_name":"MCP","slug":"mcp"},{"id":47,"name":"monitoring","display_name":"Monitoring","slug":"monitoring"},{"id":2,"name":"nlp","display_name":"NLP","slug":"nlp"},{"id":26,"name":"observability","display_name":"Observability","slug":"observability"},{"id":40,"name":"pentesting","display_name":"Pentesting","slug":"pentesting"},{"id":48,"name":"programming-examples","display_name":"Programming examples","slug":"programming-examples"},{"id":42,"name":"proxy","display_name":"Proxy","slug":"proxy"},{"id":14,"name":"rag","display_name":"RAG","slug":"rag"},{"id":56,"name":"resume-building","display_name":"Resume building","slug":"resume-building"},{"id":33,"name":"robotics","display_name":"Robotics","slug":"robotics"},{"id":30,"name":"search","display_name":"Search","slug":"search"},{"id":43,"name":"self-hosted","display_name":"Self-hosted","slug":"self-hosted"},{"id":50,"name":"static-analysis","display_name":"Static analysis","slug":"static-analysis"},{"id":18,"name":"synthetic-data","display_name":"Synthetic data","slug":"synthetic-data"},{"id":19,"name":"text-to-speech","display_name":"Text to speech","slug":"text-to-speech"},{"id":53,"name":"ui-components","display_name":"UI components","slug":"ui-components"},{"id":15,"name":"vector-database","display_name":"Vector database","slug":"vector-database"},{"id":21,"name":"video-editing","display_name":"Video editing","slug":"video-editing"},{"id":25,"name":"web-scraping","display_name":"Web scraping","slug":"web-scraping"},{"id":55,"name":"webassembly","display_name":"WebAssembly","slug":"webassembly"},{"id":23,"name":"workflow-automation","display_name":"Workflow automation","slug":"workflow-automation"}]" returns me the "expected json"