Ar apsaugotų nuo SQL injekcijų?

<?php

class sql_inject
{
    var $urlRedirect;
    var $bdestroy_session;
    var $rq;
    var $bLog;

    function sql_inject($mLog=FALSE,$bdestroy_session=FALSE,$urlRedirect=FALSE)
    {
        $this->bLog = (($mLog!=FALSE)?$mLog:'');
        $this->urlRedirect = ($urlRedirect);
        $this->bdestroy_session = $bdestroy_session;
        $this->rq = '';
    }

    function test($sRQ)
    {
        $this->rq = $sRQ;
        $sRQ = strtolower(urldecode($sRQ));
        $sRQ = str_replace( chr(0) , '' , $sRQ );
        $aValues = array();
        $aTemp = array();
        $aWords = array();
        $aSep = array(' and ',' or ');
        $sConditions = '(';
        $matches = array();
        $sSep = '';
        
        $sql_inject_patterns = array(
        '--',
        '\/\*',
        '\*\/',
        '\'',
        '"',
        '(union([\s\+\(\n\r\t]+)(select|all))',
        '[\s\+\n\r\t\(]+select[\s\+\n\r\t\)\'"`]+',
        '[\s\+\n\r\t\)`]+where[\s\+\n\r\t\(`]*',
        '[\s\+\n\r\t\)\'"`]+(from|regexp|rlike|delete|update|insert|truncate|drop|create|rename)[\s\+\n\r\t\(`]+',
        'exec',
        'cmd',
        'xp_',
        'information_schema\.',
        '[\s\+\n\r\t\)\'"`]*(or|and)[\s\+\n\r\t\(\'"]+(.*?)[\s\+\n\r\t\'"]*[=<>]+[\s\+\n\r\t\'"]*(.*?)',
        '(concat|load_file|mid|like|ord|ascii|lower|lcase|find_in_set|substring|benchmark|md5)[\s\+\n\r\t]*\('
        );
        
        if (is_int((strpos($sRQ,"#")))&&$this->_in_post('#')) return $this->detect();
        if (preg_match('/' . implode('|', $sql_inject_patterns) . '/is', $sRQ, $regs)) return $this->detect();

        if (is_int(strpos($sRQ,';'))){
            $aTemp = explode(';',$sRQ);
            if ($this->_in_post($aTemp[1])) return $this->detect();
        }

        $aTemp = preg_split('/[\s\+\)]+where[\s\+\(]*/i', $sRQ, -1, PREG_SPLIT_NO_EMPTY);
        if (count($aTemp)==1) return FALSE;
        $sConditions = $aTemp[1];
        $aWords = explode(" ",$sConditions);
        if(strcasecmp($aWords[0],'select')!=0) $aSep[] = ',';
        $sSep = '('.implode('|',$aSep).')';
        $aValues = preg_split($sSep,$sConditions,-1, PREG_SPLIT_NO_EMPTY);

        foreach($aValues as $i => $v)
        {
            if (is_int(strpos($v,'=')))
            {
                 $aTemp = explode('=',$v);
                 if (trim($aTemp[0])==trim($aTemp[1])) return $this->detect();
            }

            if (is_int(strpos($v,'<>')))
            {
                $aTemp = explode('<>',$v);
                if ((trim($aTemp[0])!=trim($aTemp[1]))&& ($this->_in_post('<>'))) return $this->detect();
            }
        }

        if (strpos($sConditions,' null'))
        {
            if (preg_match("/null +is +null/",$sConditions)) return $this->detect();
            if (preg_match("/is +not +null/",$sConditions,$matches))
            {
                foreach($matches as $i => $v)
                {
                    if ($this->_in_post($v))return $this->detect();
                }
            }
        }

        if (preg_match("/[a-z0-9]+ +between +[a-z0-9]+ +and +[a-z0-9]+/",$sConditions,$matches))
        {
            $Temp = explode(' between ',$matches[0]);
            $Evaluate = $Temp[0];
            $Temp = explode(' and ',$Temp[1]);
            if ((strcasecmp($Evaluate,$Temp[0])>0) && (strcasecmp($Evaluate,$Temp[1])<0) && $this->_in_post($matches[0])) return $this->detect();
        }
        return FALSE;
    }

    function _in_post($value)
    {
        foreach($_POST as $i => $v)
        {
             if (is_int(strpos(strtolower($v),$value))) return TRUE;
        }
        return FALSE;
    }

    function detect()
    {
        if ($this->bLog)
        {
            $fp = @fopen($this->bLog,'a+');
            if ($fp)
            {
                fputs($fp,"\r\n".date("d-m-Y H:i:s").' ['.$this->rq.'] from: '.$this->sIp = getenv("REMOTE_ADDR").'; ServerName: '.$this->servAd = getenv("SERVER_NAME"));
                fclose($fp);
                
            }
        }
        if ($this->bdestroy_session) @@session_destroy();
        if ($this->urlRedirect!=''){
             if (!headers_sent())  header("location: $this->urlRedirect");
        }
        return TRUE;
    }
}



if ($_SERVER["QUERY_STRING"] != "")
{
  $log = '/injections/sql.log' ; /// Surasau SQL injekcija
  $redirect = "../index.php" ; /// SQL injekcijos atveju pakraunamas puslapis
  $sql = new sql_inject($log,TRUE,$redirect);
  $sql->test($_SERVER["QUERY_STRING"]);
}
?>