Node.js MySQL AVG() Function

We use AVG Function to get the average value of all rows in the given column of MySQL Table.

Syntax:

AVG([column_name])

Parameters: AVG() function accepts a single parameter as mentioned above and described below.

• column_name: Column’s name from which we have to return the average 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:

index.js

const mysql = require("mysql");

let db_con  = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: '',
    database: 'gfg_db'
});

db_con.on('error', (err) => {
    console.log(err.code);
});

db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err.code);
      return;
    }

    console.log("We are connected to gfg_db database");

    // Here is the query
    let query = "SELECT AVG(salary) AS avg_salary FROM publishers";

    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.on('error', (err) => {
    console.log(err.code);
});

db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err.code);
      return;
    }

    console.log("We are connected to gfg_db database");

    // Here is the query
    let query = "SELECT AVG(salary) AS avg_salary
                 FROM publishers WHERE id < 8";

    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: