Node.js MySQL Update Statement (original) (raw)

Last Updated : 17 Feb, 2021

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:

Installing module:

npm install mysql

SQL publishers Table preview:

Example 1: Update all salary to 0.

index.js `

// 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.

index.js `

// 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