How PHP saves session sessions using MySQL _php tips

The example in this article describes how PHP saves session sessions using MySQL. Share to everyone for your reference. The specific analysis is as follows:

In many large systems generally have this function, but to separate the analysis, the online information is not too much here I organized a send to share with you

Saving session sessions with MySQL has many advantages over files:

1 in favor of distributed systems, files can only be stored on a single machine
2 for large access to the system, the use of files each session saved in a file, the directory will be super large, find session files will be more difficult.

To save a session using MySQL, you first create the sessions table:

 <?php $hostname _login = "localhost";//Server address $username _login = "root";//Us Er name $password _login = ""; Password//$data _name = "session"; Database name $login = Mysql_pconnect ($hostname _login, $username _login, $password _login) or Trigger_error (mysql_ 
Error (), e_user_error); $sql = "Show DATABASES". $data _name. "'"; If it is exist if ($rs _table=mysql_query ($sql, $login)) {if ($rs _value=mysql_fetch_array ($rs _table)) {echo database has been Exist!
   \n! "; 
  Exit ();   
}} $sql = "CREATE DATABASE $data _name"; mysql_query ($sql); Crate DB Echo database created successfully! 
\ n ";
mysql_select_db ($data _name, $login); $sql = "CREATE TABLE ' Sessions ' (' sessionkey ' varchar ') NOT NULL default ', ' Sessionarray ' blob not null, ' Sessionexp Time ' int ' unsigned not NULL default ' 0 ', PRIMARY key (' SessionKey '), key ' SessionKey ' (' SessionKey ') Engine=myisa M DEFAULT Charset=utf8 ";
New Database SQL statement mysql_query ($SQL); Echo succeeded in creating a new database table! ";?> 

The

Mysqlsession class is as follows:

<?php class Mysqlsession {//Note the page with session usage.
Page must be below, the beginning of the page can not be left blank. Private $DB _server = "localhost"; Database server host name private $DB _name = ""; Database name private $DB _user = "root"; MYSQL database access User name private $DB _pass = ""; 
MYSQL database access password private $DB _select_db = ""; Private $SESS _life = 1440;
Maximum length of session, per second.
Private $SESS _life = 0;
  Function mysqlsession (& $sessionDB) {//session_write_close ();
  $this->db_name = & $sessionDB;
  $this->sess_life = Get_cfg_var ("Session.gc_maxlifetime");
  Session_module_name (' user '); Session_set_save_handler (Array (& $this, ' Sess_open '), Array (& $this, ' Sess_close '), Array (& $this, ' ses
  S_read '), Array (& $this, ' Sess_write '), Array (& $this, ' Sess_destroy '), Array (& $this, ' sess_gc '));
Session_Start (); function Sess_open ($save _path, $session _name) {//Open database connection if (! $this->db_select_db = mysql_pconnect ($this->db_ SERVER, $this->db_user, $this->db_pass)) {echo "Sorry! 
  MYSQL Error:can ' t connect to $this->db_server as $DB _user "; 
  echo "MySQL Error:", mysql_error (); 
  Die } if (! mysql_select_db ($this->db_name, $this->db_select_db)) {echo sorry! 
  MYSQL error:unable to select database $this->db_name "; 
  Die 
return true; 
function Sess_close () {return true; The function Sess_read ($SessionKey) {$Query = "Select Sessionarray from sessions WHERE SessionKey = '". $SessionKey. " ' and Sessionexptime > '.
    Time ();
    Expired does not read. 
  $Result = mysql_query ($Query, $this->db_select_db); 
  if (list ($SessionArray) = Mysql_fetch_row ($Result)) {return $SessionArray; 
return false;
  function Sess_write ($SessionKey, $VArray) {$SessionExpTime = time () + $this->sess_life; 
  Update session expiration, session expiration = Last Update time + Session maximum usage length $SessionArray = addslashes ($VArray); $Query = "INSERT into sessions (Sessionkey,sessionexptime,sessionarray) VALUES ('". $SessionKey. "', '". $SessionExPtime. "', '". $SessionArray. "')"; 
  $Result = mysql_query ($Query, $this->db_select_db); if (! $Result) {$Query = "UPDATE sessions SET sessionexptime = '". $SessionExpTime. "', Sessionarray = '". $SessionArra Y. "' WHERE SessionKey = ' ". $SessionKey." ' and Sessionexptime > ". 
      Time (); 
  $Result = mysql_query ($Query, $this->db_select_db); 
return $Result; 
  The function Sess_destroy ($SessionKey) {$Query = "DELETE from sessions WHERE SessionKey = '". $SessionKey. "'"; 
  $Result = mysql_query ($Query, $this->db_select_db); 
return $Result; The function sess_gc ($maxlifetime) {//This garbage scavenger system call.
The default is 1440 seconds to clear once.
  Parameters can be set inside the php.ini. $Query = "DELETE from sessions WHERE Sessionexptime <". 
  Time (); 
  $Result = mysql_query ($Query, $this->db_select_db); 
Return Mysql_affected_rows ($this->db_select_db);
 }}?>

Usage: In the original use of Session_Start, replace with $session = new Mysqlsession ()

Note: To open the database before this program is included, the main program cannot close the database before exiting, or there will be an error.

I hope this article will help you with your PHP program design.