$db_host = 'localhost';
$db_user = 'root';
$db_password = '';
$db_name = 'allonpage';
$con = new mysqli('localhost', $db_user, $db_password, $db_name);
if ($con->connect_error)
die('Connection Error: ' . $con->connect_error);
if (!$con->query("SET c=1"))
{
echo "<pre>";
print_r($con->error_list);
echo "</pre>";
}
$con->close();
/*
run:
Array
(
[0] => Array
(
[errno] => 1193
[sqlstate] => HY000
[error] => Unknown system variable 'c'
)
)
*/