<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
{
 echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

 mysqli_query($con,"DELETE FROM Persons WHERE LastName='Griffin'");

mysqli_close($con);
?>

UPDATE Persons
    set LastName = ''
WHERE
    id = ?