{"id":3962,"date":"2024-07-16T11:22:13","date_gmt":"2024-07-16T04:22:13","guid":{"rendered":"https:\/\/www.sqlservertutorial.net\/?page_id=3962"},"modified":"2024-07-22T07:53:08","modified_gmt":"2024-07-22T00:53:08","slug":"nodejs-sql-server-delete","status":"publish","type":"page","link":"https:\/\/www.sqlservertutorial.net\/nodejs-sql-server\/nodejs-sql-server-delete\/","title":{"rendered":"Node.js SQL Server: Delete"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to delete data from a table in SQL Server from a Node.js application.<\/p>\n\n\n\n

This tutorial begins where\u00a0the Pagination in Node.js tutorial<\/a>\u00a0left off.<\/p>\n\n\n\n

Deleting author by ID #<\/a><\/h2>\n\n\n\n

Step 1. Create a new file named delete.js<\/code> within the project directory:<\/p>\n\n\n\n

Step 2. Define a new function called deleteAuthorById<\/code> in the delete.js<\/code> file:<\/p>\n\n\n

import<\/span> sql from<\/span> 'mssql'<\/span>;\nimport<\/span> { config } from<\/span> '.\/config.js'<\/span>;\n\nconst<\/span> deleteAuthorById = async<\/span> (id) => {\n  try<\/span> {\n    \/\/ Connect to the database<\/span>\n    const<\/span> pool = await<\/span> sql.connect(config);\n\n    \/\/ Execute the query<\/span>\n    const<\/span> result = await<\/span> pool\n      .request()\n      .input('id'<\/span>, sql.Int, id)\n      .query(`DELETE  FROM Authors WHERE AuthorID = @id`<\/span>);\n\n    if<\/span> (result?.rowsAffected?.length >= 1<\/span>) {\n      console<\/span>.log(`${result.rowsAffected.length}<\/span> row(s) deleted!`<\/span>);\n    }\n  } catch<\/span> (err) {\n    console<\/span>.error(err);\n  }\n};\n\nexport<\/span> { deleteAuthorById };<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
How it works.<\/p>\n\n\n\n
First, import sql<\/code> object from mssql<\/code> package and config<\/code> object from the config.js<\/code> module:<\/p>\n\n\n
import<\/span> sql from<\/span> 'mssql'<\/span>;\nimport<\/span> { config } from<\/span> '.\/config.js'<\/span>;<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
The mssql<\/code> package provides API to interact with the SQL Server. The config<\/code> is an object that contains database parameters for the connection.<\/p>\n\n\n\n
Second, connect to the database using the provided configuration object:<\/p>\n\n\n
const<\/span> pool = await<\/span> sql.connect(config);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
The sql.connect()<\/code> function returns a ConnectionPool<\/code> object which allows you to execute queries.<\/p>\n\n\n\n
Third, execute a DELETE<\/code> statement:<\/p>\n\n\n
const<\/span> result = await<\/span> pool\n  .request()\n  .input('id'<\/span>, sql.Int, id)\n  .query(`DELETE  FROM Authors WHERE AuthorID = @id`<\/span>);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
In this statement:<\/p>\n\n\n\n