Change the user of the specified database connection in PHP

  //  w  w w  .  jav  a2 s .com
<?php
    $con=mysqli_connect("localhost","root","","test");
    
    // Check connection
    if (mysqli_connect_errno()){
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }
   
    // Reset all and select a new database
    mysqli_change_user($link, "root", "", "test");
   
    mysqli_close($con);
?>