Using Advanced Functions to Maintain the State of Applications with PHP Sessions - Getting the MySQL-based session module complete: listing MySQL processing classes (
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As I promised, here’s the source code for the couple of MySQL processing classes used within the definition of the prior callback functions:
class MySQL {
var $conId; // connection identifier
var $host; // MySQL host
var $user; // MySQL username
var $password; // MySQL password
var $database; // MySQL database
// constructor
function MySQL($options=array()){
// validate incoming parameters
if(count($options)>0){
foreach($options as $parameter=>$value){
if(empty($value)){
trigger_error('Invalid parameter
'.$parameter,E_USER_ERROR);
}
$this->{$parameter}=$value;
}
// connect to MySQL
$this->connectDB();
}
else {
trigger_error('No connection parameters were
provided',E_USER_ERROR);
}
}
// connect to MYSQL server and select database
function connectDB(){
if(!$this->conId=mysql_connect($this->host,$this-
>user,$this->password)){
trigger_error('Error connecting to the
server',E_USER_ERROR);
}
if(!mysql_select_db($this->database,$this->conId)){
trigger_error('Error selecting
database',E_USER_ERROR);
}
}
// perform query
function query($query){
if(!$this->result=mysql_query($query,$this->conId)){
trigger_error('Error performing query
'.$query,E_USER_ERROR);
}
// return new Result object
return new Result($this,$this->result);
}
}
class Result {
var $mysql; // instance of MySQL object
var $result; // result set
function Result(&$mysql,$result){
$this->mysql=&$mysql;
$this->result=$result;
}
// fetch row
function fetchRow(){
return mysql_fetch_array($this->result,MYSQL_ASSOC);
}
// count rows
function countRows(){
if(!$rows=mysql_num_rows($this->result)){
return false;
}
return $rows;
}
// count affected rows
function countAffectedRows(){
if(!$rows=mysql_affected_rows($this->mysql->conId)){
trigger_error('Error counting affected
rows',E_USER_ERROR);
}
return $rows;
}
// get ID from last inserted row
function getInsertID(){
if(!$id=mysql_insert_id($this->mysql->conId)){
trigger_error('Error getting ID',E_USER_ERROR);
}
return $id;
}
// seek row
function seekRow($row=0){
if(!mysql_data_seek($this->result,$row)){
trigger_error('Error seeking data',E_USER_ERROR);
}
}
function getQueryResource(){
return $this->result;
}
}
Right. Now that I showed you the pair of MySQL processing classes used by the previous callback functions, let me set up an example which implements this user-defined session storage system, by the respective “session_set_save_handler()” function. Have a look at the code listed below:
// include classes
require_once 'mysqlclass.php';
require_once 'resultclass.php';
// connect to MySQL
$db=&new MySQL(array
('host'=>'localhost','user'=>'user','password'=>'password',
'database'=>
'database'));
// use 'session_set_save_handler function'
session_set_save_handler
('openSession','closeSession','readSession','writeSession',
'destroySession',
'gcSession');
session_start();
// register some session variables
$_SESSION['firstname']='Alejandro';
$_SESSION['lastname']='Gervasio';
That’s it. After connecting to MySQL, the above script uses the “session_set_save_handler()” in order to register all the callback functions that you saw before, and as a result, all the session data will be stored in a sample “sessions” database table. By tweaking the correct session settings within the php.ini file, in conjunction with implementing this MySQL-driven session storage module, it’s possible to construct a more efficient and secure session management mechanism than the one provided as default by PHP. As you’ve seen, the experience can be instructive and educational, so why don’t you try it for yourself?
Wrapping up
That’s all for the moment. Over this second part of the series, I explored the powerful “session_save_path()” and “session_set_save_handler()” functions. Particularly, this last function can be extremely helpful for developing a custom session management system that uses a MySQL database table for storing session-related data, instead of conventional flat files.
Since this approach is used in many situations where a personalized session storage mechanism is preferred over the default offered by PHP, in the last article, I’ll encapsulate all the pertinent callback functions defined before within a class. In this way, the entire session handling process can be centralized at only one handler object. Therefore, don’t miss the next part!
| | Discuss Using Advanced Functions to Maintain the State of Applications with PHP Sessions | | | | | | | In this part of the series, you'll learn how to tweak the PHP session storage... | | | | | | Hi Alejandro, I greatly appreciate your efforts in bringing us these useful... | | | | | | Hi Rafael,
Thank you for commenting on my PHP article. Regarding your question,... | | | | | | Hi Alejandro, thank you so much for the example, it worked to perfection. I'm so... | | | | | | Hi Rafael,
Thank you for the kind word on my PHP articles, and certainly I feel... | | | | | | Hello again Alejandro, I run into a bug as I got my application onto the production... | | | | | | Hi Rafael,
Thank you for posting your comments. Concerning your particular... | | | | | | Hi Alejandro, a million thanks for your help. I stayed awake for a long time last... | | | | | | Hi Rafael. I'm glad to know you fixed up the problem regarding the use of mysqli and... | | | | | | Hi alejandro
Its me again, ive been making your tutorial as my book, im working... | | | | | | Hi Alejandro,
thanks for this wonderful tutorial.
When i tried to use your... | | | | | | Hi Roy,
Thanks for posting your comments, and I’m glad to know you’re learning... | | | | | | Thansk again for the comments. In fact, $id isn't necessary when coding this... | | | | | | Hello Alejandro,
Thanks for the prompt reply. Im still confused, on your reply you... | | | | | | Hello Alejandro,
I temporarily placed this code inside the writeSession()... | | | | | | Hi Roy,
with your last example, I see the possible reason of your problem.... | | | | | | Hello alehandro...
i set up my expiry as a timestamp, and that the expiry colum... | | | | | | Hello Roy,
Thanks for the comments. Using "time()" to insert your timestamps is a... | | | | | | >>> Post your comment now! | | | | | |
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