<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");

// Check connection
if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

mysqli_query($con,"CREATE TABLE myPersons LIKE Persons");

$newpers="Da'Silva"

// This query will fail, cause we did not escape $newpers
mysqli_query($con,"INSERT into myPersons (Lastname) VALUES ('$newpers')");

$newpers=mysqli_real_escape_string($con,$newpers);

// This query will work, cause we escaped $newpers
mysqli_query($con,"INSERT into myPersons (Lastname) VALUES ('$newpers')");

mysqli_close($con);
?>