connect_php_mysql.php

<?php
  // Create a pdo instance 
  $host = 'localhost';
  $database_name = 'databasename';
  $username='username by default it is root';
  $password='the password associated with the current user';
  
  try{
    // check if there is exception
    $pdo = new PDO("mysql:host=$host;dbname=$database_name","$username","$password");
  
    // now we've connected successfully to $database_name database
    // and we can do whatever we want with it.
  }
  catch(PDOException $e){
    // show a message explaining what is goining wrong.
    echo $e->getMessage();
  }
 
?>