Node.js MySQL Update Statement

Node.js is an open-source platform for executing JavaScript code on the server-side. It can be downloaded from here. MySQL is an open-source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL). It is the most popular language for adding, accessing, and managing content in a database. Here we will use the MySQL as a database for our node application. It can be downloaded from here.

Update statement: Update command is a DML command which is used for manipulating the records of a table.

Syntax:

UPDATE [table_name] SET column_A = value_A, column_B = value_B, ... WHERE condition

Modules:

• mysql: mysql module is used for interaction between the MySQL server and the node.js application.

Installing module:

npm install mysql

SQL publishers Table preview:

Example 1: Update all salary to 0.

// Importing module const mysql = require("mysql"); // Creating connection let db_con = mysql.createConnection({  host: "localhost",  user: "root",  password: '',  database: 'gfg_db' }); db_con.connect((err) => {  if (err) {  console.log("Database Connection Failed !!!", err);  return;  }  console.log("We are connected to gfg_db database");  // Creating Query  let query = "UPDATE publishers SET salary=0";  // Executing Query  db_con.query(query, (err, rows) => {  if(err) throw err;  console.log(rows);  }); }); 

Run index.js file using below command:

node index.js

Console Output: Using the Where clause is very important in UPDATE. Otherwise, the whole table may become useless.

Example 2: Increase the salary of publishers by 1000 who are earning more than 7000.

// Importing module const mysql = require("mysql"); // Creating connection let db_con = mysql.createConnection({  host: "localhost",  user: "root",  password: '',  database: 'gfg_db' }); db_con.connect((err) => {  if (err) {  console.log("Database Connection Failed !!!", err);  return;  }  console.log("We are connected to gfg_db database");  // Generating Query  let query =  "UPDATE publishers SET salary=salary+1000 WHERE salary > 7000";  // Executing Query  db_con.query(query, (err, rows) => {  if(err) throw err;  console.log(rows);  }); }); 

Run index.js file using below command:

node index.js

Console Output: Notice previous and current salary of users with id 6, 8