PHP mysqli_sqlstate() Function

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

// Table Persons already exists, so we should get an error
$sql="CREATE TABLE Persons (Firstname VARCHAR(30),Lastname VARCHAR(30),Age INT)"
if (!mysqli_query($con,$sql))
  {
  echo "SQLSTATE error: ". mysqli_sqlstate($con);
  }

// Close connection
mysqli_close($con);
?>