使用session_set_save_handler函数重载SESSION存储方式之MYSQL

<?
   $DB_SERVER = "server"; /* database server hostname */
   $DB_NAME = "dbname"; /* database name */
   $DB_USER = "root"; /* database user */
   $DB_PASS = "*************"; /* database password */

   $DB_SELECT_DB = "";
   $SESS_LIFE = get_cfg_var("session.gc_maxlifetime");

   function sess_open($save_path, $session_name) {
   global $DB_SERVER, $DB_NAME, $DB_USER, $DB_PASS, $DB_SELECT_DB;

   if (! $DB_SELECT_DB = mysql_pconnect($DB_SERVER, $DB_USER, $DB_PASS)) {
   echo "SORRY! MYSQL ERROR : Can't connect to $DB_SERVER as $DB_USER";
   echo "MySQL Error: ", mysql_error();
   die;
   }

   if (! mysql_select_db($DB_NAME, $DB_SELECT_DB)) {
   echo "SORRY! MYSQL ERROR : Unable to select database $DB_NAME";
   die;
   }

   return true;
   }

   function sess_close() {
   return true;
   }

   function sess_read($SessionKey){
global $DB_SELECT_DB, $SESS_LIFE;
$Query = "SELECT SessionArray FROM cdb_global_sessions WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time();
$Result = mysql_query($Query, $DB_SELECT_DB);

   if (list($SessionArray) = mysql_fetch_row($Result)) {
   return $SessionArray;
   }

   return false;
   }

   function sess_write($SessionKey, $VArray) {
   global $DB_SELECT_DB, $SESS_LIFE;

   $SessionExpTime = time() + $SESS_LIFE;
   $SessionArray = addslashes($VArray);

   $Query = "INSERT INTO cdb_global_sessions (SessionKey,SessionExpTime,SessionArray) VALUES ('".$SessionKey."','".$SessionExpTime."','".$SessionArray."')";
   $Result = mysql_query($Query, $DB_SELECT_DB);

   if (!$Result){
   $Query = "UPDATE cdb_global_sessions SET SessionExpTime = '".$SessionExpTime."', SessionArray = '".$SessionArray."' WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time();
   $Result = mysql_query($Query, $DB_SELECT_DB);
   }
   return $Result;
   }

   function sess_destroy($SessionKey) {
   global $DB_SELECT_DB;

   $Query = "DELETE FROM cdb_global_sessions WHERE SessionKey = '".$SessionKey."'";
   $Result = mysql_query($Query, $DB_SELECT_DB);

   return $Result;
   }

   function sess_gc($maxlifetime) {
   global $DB_SELECT_DB;

   $Query = "DELETE FROM cdb_global_sessions WHERE SessionExpTime < " . time();
   $Result = mysql_query($Query, $DB_SELECT_DB);

   return mysql_affected_rows($DB_SELECT_DB);
   }

   session_set_save_handler(
   "sess_open",
   "sess_close",
   "sess_read",
   "sess_write",
   "sess_destroy",
   "sess_gc");

session_start();
   ?>