Node.js MySQL Count() Function
We use the COUNT() function in MySQL to count a number of rows in a column satisfying the WHERE clause.
Syntax:
COUNT([column_name])
Parameters: COUNT() function accepts a single parameter as mentioned above and described below.
- column_name: Column’s name from which we have to return the count value.
Module Installation: Install the mysql module using the following command:
npm install mysql
Database: Our SQL publishers table preview with sample data is shown below:
Example 1: Count publishers having id greater than 5
index.js
const mysql = require( "mysql" ); 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" ); // Here is the query let query = "SELECT COUNT(id) AS id_count FROM publishers WHERE id > 5" ; db_con.query(query, (err, rows) => { if (err) throw err; console.log(rows); }); }); |
Run the index.js file using the following command:
node index.js
Output:
Example 2:
index.js
const mysql = require( "mysql" ); 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" ); // Here is the query let query = "SELECT COUNT(salary) AS salary_count FROM publishers WHERE salary BETWEEN 5000 AND 10000" ; db_con.query(query, (err, rows) => { if (err) throw err; console.log(rows); }); }); |
Run the index.js file using the following command:
node index.js
Output: