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: