Save session with MySQL

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This example describes how PHP uses MySQL to save session sessions. Share to everyone for your reference. The specific analysis is as follows:

in many large systems generally have this function, but to separate out the analysis, the online information is not too much here I collated an article sent to share with you

using MySQL to save session sessions has many advantages over files:

1) for distributed systems, files can only be saved on a single machine

2) for large-scale system, the use of files when each session is 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 session table:

<?php$hostname_login = "localhost";//Server address$ Username_login = "root"; User 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 like '". $data _name. "'"; If it is Existif ($rs _table=mysql_query ($sql, $login)) {if ($rs _value=mysql_fetch_array ($rs _table)) {echo "Database already exists!   \n! ";   Exit ();   }} $sql = "CREATE DATABASE $data _name"; mysql_query ($sql); Crate Databaseecho "Database created successfully! \ n "; mysql_select_db ($data _name, $login); $sql = "CREATE TABLE ' Sessions ' (' sessionkey ' varchar) not NULL default ' ', ' Sessio NArray ' blob not null, ' sessionexptime ' int (a) unsigned NOT null default ' 0 ', PRIMARY key (' SessionKey '), key ' SessionKey ' (' SessionKey ')) Engine=myisam DEFAULT Charset=utf8 "; New Database SQL statement mysql_query ($sql); echo "Successfully created a new database table! ";? 

The Mysqlsession class is as follows:

<?php class Mysqlsession {//Note in the page with session.  The page must be shelf and the page cannot be left blank at the beginning. 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;  The maximum length of time to use the session, in seconds.  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 (& $t  His, ' Sess_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-&gt ;D B_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 $this->db_name ";     Die   } return true;   } function Sess_close () {return true; } function Sess_read ($SessionKey) {$Query = "Select Sessionarray from sessions WHERE SessionKey = '". $SessionKey. "' and Sessionexptime >".    Time ();    Expires without reading.     $Result = mysql_query ($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 time, session expiration = Last Update time + Session maximum usage $SessionArray = addslashes ($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 = '". $SessionA Rray. "' WHERE SessionKey = ' ". $SessionKey." ' and Sessionexptime >. "       Time ();     $Result = mysql_query ($Query, $this->db_select_db);   } return $Result;     } function Sess_destroy ($SessionKey) {$Query = "DELETE from sessions WHERE SessionKey = '". $SessionKey. "'";       $Result = mysql_query ($Query, $this->db_select_db);   return $Result; } function sess_gc ($maxlifetime) {//This garbage cleaner system is called.    The default is 1440 seconds to clear once.    Parameters can be set in 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 place where the original session_start is used, replace with $session = new Mysqlsession ()

Note: To open the database before the main program exits, the database cannot be closed before the program is included, or an error will occur.

I hope this article is helpful to everyone's PHP programming

Save session with MySQL