Custom Session Manager in PHP

<?PHPclassCustomsessionImplementssessionhandlerinterface{Private $link; Private $lifetime;  Public functionOpen$savePath,$session _name){          $this->lifetime=Get_cfg_var(' Session.gc_maxlifetime '); $this->link=Mysqli_connect(' localhost ', ' root ', ' root ', ' session_test '); Mysqli_query($this->link, "SET names UTF8"); if($this-link) {              return true; }          return false; }       Public functionClose () {Mysqli_close($this-link); return true; }       Public functionRead$session _id){              $sql= "Select *from sessions where Session_id= ' {$session _id} ' and Session_expires >". Time(); $result=Mysqli_query($this->link,$sql); if(mysqli_num_rows($result)){                  return Mysqli_fetch_array($result) [' Session_data ']; }              return""; }       Public functionWrite$session _id,$session _data){              $newExp= Time()+$this-lifetime; //The first query is whether the specified session_id exists, and if it is the equivalent of the update data, the data is written              $sql= "SELECT * from sessions where session_id={'$session _id‘}"; $result=Mysqli_query($this->link,$sql); if(mysqli_num_rows($result) ==1){                  $sql= "UPDATE Sessions set session_expires= ' {$newExp} ', Session_data= ' {$session _data} ' where session_id= ' {$session _id}‘ "; }Else{                  $sql= "INSERT into sessions values (' {$session _id}‘,‘$session _data‘,‘{$newExp}‘)"; }              Mysqli_query($this->link,$sql); return mysqli_affected_rows($this->link) ==1; }               Public functionDestroy$session _id){              $sql= "DELETE from sessions where Session_id= ' {$session _id}‘"; Mysqli_query($this->link,$sql); return mysqli_affected_rows($this->link) ==1; }       Public functiongc$maxlifetime){              $sql= "DELETE from sessions where session_expires<". Time(); Mysqli_query($this->link,$sql); if(mysqli_affected_rows($this->link) >0){                  return true; }              return false; }}

<?PHPHeader("Content-type:text/html;charset=utf-8"); require_once' Customsession.php '; $customSession=Newcustomsession (); Ini_set(' Session.save_handler ', ' user '); Session_set_save_handler($customSession,true); Session_Start(); $_session[' Name ']= ' admin '; $_session[' pwd ']= ' 123456 ';

// destroy the session, delete the < from the database;? PHP      require_once ' customsession.php ';     $customSession=new  customsession ();     Ini_set (' Session.save_handler ', ' user ');     Session_set_save_handler ($customSession,true);     Session_Start ();     Session_destroy ();

Custom Session Manager in PHP