خطا در اتصال اسکریپت به پایگاه داده

set_time_limit(0);
date_default_timezone_set('Asia/Tehran');
include("connection.php");
include("constant.php");

class MYSQLi_DB {

var $connection;

function MYSQLi_DB() {
$this->connection = mysqli_connect(SQL_SERVER, SQL_USER, SQL_PASS, SQL_DB) or die(mysqli_error());
}
function query($query) {
return $this->connection->query($query);
}

};

class MYSQL_DB {

var $connection;

function MYSQL_DB() {
$this->connection = mysql_connect(SQL_SERVER, SQL_USER, SQL_PASS) or die(mysql_error());
mysql_select_db(SQL_DB, $this->connection) or die(mysql_error());
}

function mysql_exec_batch ($p_query, $p_transaction_safe = true) {
if ($p_transaction_safe) {
$p_query = 'START TRANSACTION;' . $p_query . '; COMMIT;';
};
$query_split = preg_split ("/[;]+/", $p_query);
foreach ($query_split as $command_line) {
$command_line = trim($command_line);
if ($command_line != '') {
$query_result = mysql_query($command_line);
if ($query_result == 0) {
break;
};
};
};
return $query_result;
}

function query($query) {
return mysql_query($query, $this->connection);
}
};

if(DB_TYPE) {
$database = new MYSQLi_DB;
}
else {
$database = new MYSQL_DB;
}
?>