Run Adminer with custom Session class (in database rather than file system)

runAdminer.php

<?php
include('php/ini.php'); //get mySQL settings
$SESSIONTAB = 'session'; //table for PHP sessions

/*****************************| MYSQLI CONNECTION FUNCTION |*****************************/
/**
	* Simple MySQLi abstraction layer
	*
	* @param resource $mysqli The MySQLi connection link
	* @param string   $query  The MySQL query for prepaired statement
	* @param array    $v      The parameters to replace ? in $query. First element must be the type
	* @param integer  $o      Option for more debug infos [0]=no infos(default) [1]=adding debug infos
	*
	* @return array [for select]=associative array of table result  [for everything else]=associative array with affectedRows,info and insertID
	*
	* @author Dominik Wilkowski <hi@dominik-wilkowski.com>
	* @copyright 2013 Dominik Wilkowski
	*/
$connect2DB = function($mysqli, $query, $v=array(), $o=0) {

	if($mysqli -> connect_errno) {
		return array('info'=>array('error'=>'Connect failed: '.$mysqli->connect_error)); //error handling here
		exit();
	}

	if($v && (substr_count($query,"?")!=strlen($v[0]) || strlen($v[0])!=((count($v)-1)>=0 ? (count($v)-1) : 0))) {
		return array('info'=>array('error'=>'Placeholders are unequal! placeholders:'.substr_count($query,"?").', replacements:'.strlen($v[0]).', param:'.(count($v)-1).' ('.$v[0].')')); //error handling here...
		exit();
	}

	if($res = $mysqli->prepare($query)) {
			//dynamically bind all $v
			if($v) {
			$values=array($v[0]);
			for($i=1; $i<count($v); $i++) {
				${'bind'.$i}=$v[$i];
				$values[]=&${'bind'.$i};
			}
			call_user_func_array(array($res,'bind_param'),$values);
		}
		$res -> execute();

		//bind all table rows to result
		if(strtolower(substr($query,0,6))=="select") {
			$field=$fields=$tempRow=array();
			$meta=$res->result_metadata();
			while($field=$meta->fetch_field()) {
				$fieldName=$field->name;
				$fields[]=&$tempRow[$fieldName];
			}
			$meta -> free_result();
			call_user_func_array(array($res,"bind_result"),$fields);

			//return associative array
			$results=array();
			$i=0;
			while($res->fetch()) {
				$results["res"][$i]=array();
				foreach($tempRow as $k=>$v2) $results["res"][$i][$k] = $v2;
				$i++;
			}
			$res->free_result();

		}
		else { //return infos about the query

			if($mysqli->warning_count) {
				if($err=$mysqli->query("SHOW WARNINGS")) {
					$row=$err->fetch_row();
					$results["info"]["error"].=$row[0].' ('.$row[1].'): '.$row[2];
					$err->close();
				}
			}
			$results["info"]["affectedRows"]=$mysqli->affected_rows;
			$results["info"]["info"]=$mysqli->info;
			$results["info"]["insertID"]=$mysqli->insert_id;
		}

		$res->close();
	}

	if($o===1) { //adding debug infos
		$q=$query;
		for($i=1;$i<count($v);$i++) $q=preg_replace("/\?/",(substr($v[0],($i-1),1)=="s" ? '"' : '').$v[$i].(substr($v[0],($i-1),1)=="s" ? '"' : ''),$q,1);
		$results["info"]["query"]=$q;
		$results["info"]["param"]=json_encode($v);
	}

	if(strtolower(substr($query,0,6))=="update" || strtolower(substr($query,0,6))=="delete") { //optimize at update and delete
		preg_match_all('/((update|delete) `(.*)` )/i',$query,$tables);
		foreach($tables[3] as $t) $mysqli->query('OPTIMIZE TABLE '.$t);
	}

	return $results;
};


/**
	* SESSION HANDLER CLASS
	*
	* @author Dominik Wilkowski
	*/
class sessionDBHandler {
	public function __construct() {
		session_set_save_handler(
			array($this, "_open"),
			array($this, "_close"),
			array($this, "_read"),
			array($this, "_write"),
			array($this, "_destroy"),
			array($this, "_gc")
		);
		register_shutdown_function('session_write_close');
	}

	/**
	* open mysql connection
	*/
	public function _open() {
		global $sessCon;

		$sessCon=new mysqli(HOST,USER,PW,DATABASE); //mysqli connection
	}

	/**
	* close mysql connection
	*/
	public function _close() {
		global $sessCon;

		$sessCon->close();
	}

	/**
		* read session data
		*
		* @param string  $id  Session ID
		*
		* @return string Session data saved in DB
		*/
	public function _read($id) {
		global $sessCon;
		global $connect2DB;
		global $SESSIONTAB;

		$qRes=$connect2DB($sessCon,'select `data` from `'.$SESSIONTAB.'` where `ID`=?',array("s",$id));

		if(!empty($qRes["res"][0]["data"])) return $qRes["res"][0]["data"];
		else return '';
	}

	/**
		* write session data
		*
		* @param string  $id    Session ID
		* @param string  $data  Session Data
		*
		* @return bool
		*/
	public function _write($id,$data) {
		global $sessCon;
		global $connect2DB;
		global $SESSIONTAB;

		$qRes=$connect2DB($sessCon,'select `ID` from `'.$SESSIONTAB.'` where `ID`=?',array("s",$id));

		$param=array(); //buliding SQL query parameters
		$param[0]="sis";
		$param[]=$id;
		$param[]=time();
		$param[]=$data;
		if(!empty($qRes["res"][0]["ID"])) {
			$param[0].="s";
			$param[]=$id;
		}

		$qRes=$connect2DB($sessCon,(!empty($qRes["res"][0]["ID"]) ? 'update' : 'insert').' `'.$SESSIONTAB.'` set `ID`=?, `access`=?, `data`=?'.(!empty($qRes["res"][0]["ID"]) ? ' where `ID`=?' : ''),$param);

		if($qRes["info"]["affectedRows"]>0) return true;
		else return false;
	}

	/**
		* destroty session
		*
		* @param string  $id  Session ID
		*
		* @return bool
		*/
	public function _destroy($id) {
		global $sessCon;
		global $connect2DB;
		global $SESSIONTAB;

		$qRes=$connect2DB($sessCon,'delete from `'.$SESSIONTAB.'` where `ID`=?',array("s",$id));

		if($qRes["info"]["affectedRows"]>0) return true;
		else return '';
	}

	/**
		* clean sessions
		*
		* @param int  $max  Session life time
		*
		* @return bool
		*/
	public function _gc($max) {
		global $sessCon;
		global $connect2DB;
		global $SESSIONTAB;

		$qRes=$connect2DB($sessCon,'delete from `'.$SESSIONTAB.'` where `access`<?',array("i",(time()-$max)));

		if($qRes["info"]["affectedRows"]>0) return true;
		else return false;
	}
}

new sessionDBHandler(); //save sessions into the database
session_start(); //login session

include "adminer.php";

?>