Question

I am having a small problem with my PHP MySQL Select. The function is inside of a PHP class. Here is the error I get:

Warning: mysql_fetch_array() expects parameter 1 to be resource,
integer given in C:\xampp\htdocs\include\database.php on line 59
Warning: extract() expects parameter 1 to be array, null given in
C:\xampp\htdocs\include\database.php on line 59

The function just simply updates the database to show what browser and OS they visited the site with. The function is called from another file that is called by an AJAX call that uses POST to send the data about the OS and browser that was gathered from a Javascript file. It only fails if there is an entry of the IP address already in the database. If there is no IP Address entry in the database it succeeds in creating one.

Here is my code:

function addStat($browser, $os){
    $IE = 0; $Firefox = 0; $Safari = 0; $Opera = 0; $Chrome = 0; $otherb = 0;
    $Windows = 0; $Linux = 0; $Mac = 0; $Android = 0; $iOS = 0; $otheros = 0;
    $ql = 0; $totalVisits = 0;
    $ip = ip2long($_SERVER['REMOTE_ADDR']);
    $q1 = mysql_query("SELECT * FROM " . DB_STATS . " WHERE ip='$ip'", $this->connection);
    if (mysql_num_rows($q1)==0){
        $browser = mysql_real_escape_string($browser);
        $os = mysql_real_escape_string($os);
        switch($browser){
            case "Internet Explorer":
                $IE += 1;
            break;
            case "Firefox":
                $Firefox += 1;
            break;
            case "Safari":
                $Safari += 1;
            break;
            case "Opera":
                $Opera += 1;
            break;
            case "Chrome":
                $Chrome += 1;
            break;
            default:
                $otherb += 1;
            break;
        }
        switch($os){
            case "Windows":
                $Windows += 1;
            break;
            case "Mac OS X":
                $Mac += 1;
            break;
            case "Linux":
                $Linux += 1;
            break;
            case "Android":
                $Android += 1;
            break;
            case "iOS":
                $iOS += 1;
            break;
            default:
                $otheros += 1;
            break;
        }
        $q = $this->query("INSERT INTO " . DB_STATS . " VALUES (null, '$ip', '$Chrome', '$IE', '$Firefox', '$Opera', '$Safari', '$otherb', '$Windows', '$Mac', '$Linux', '$Android' , '$iOS' , '$otheros', 1)");
        if ($q == true){
           return(1);
        }
        else{
           return(0);
        }
    }
    else if (mysql_num_rows($q1)==1){
        extract(mysql_fetch_array($ql));
        switch($browser){
            case "Internet Explorer":
                $IE += 1;
            break;
            case "Firefox":
                $Firefox += 1;
            break;
            case "Safari":
                $Safari += 1;
            break;
            case "Opera":
                $Opera += 1;
            break;
            case "Chrome":
                $Chrome += 1;
            break;
            default:
                $otherb += 1;
            break;
        }
        switch($os){
            case "Windows":
                $Windows += 1;
            break;
            case "Mac OS X":
                $Mac += 1;
            break;
            case "Linux":
                $Linux += 1;
            break;
            case "Android":
                $Android += 1;
            break;
            case "iOS":
                $iOS += 1;
            break;
            default:
                $otheros += 1;
            break;
        }
        $totalVisits += 1;
        $q = $this->query("UPDATE " . DB_STATS . " set Chrome='$Chrome', IE='$IE', Firefox='$Firefox', Opera='$Opera', Safari='$Safari', otherb='$otherb', Windows='$Windows', Mac='$Mac', Linux='$Linux', Android='$Android' , iOS='$iOS' , otheros='$otheros', totalVisits='$totalVisits'");
        if ($q == true){
           return(1);
        }
        else{
           return(0);
        }
    }
    else{
        return(-1);
    }
}

I hope everything made sense and that someone will help.

Answer 1

I see it now — you used $ql (lower case L) when you intend to use $q1. Let this be a lesson against using very short variable names or very similar names.

// $ql was initialized to 0
$ql = 0; $totalVisits = 0;

// $q1 holds the result resource
extract(mysql_fetch_array($q1));

It is not advisable to call extract() on the output of mysql_fetch_array() unless you also specify the second parameter MYSQL_ASSOC as the fetch type. By default it returns both numeric and associative indices for each column.

extract(mysql_fetch_array($q1, MYSQL_ASSOC));
// Or better
extract(mysql_fetch_assoc($q1));

In general, I would probably advise against using extract() in most any situation, since it results in numerous variables dumped into the global namespace, in particular when you have done SELECT * without being specific about which columns are selected. Better to access them via their array:

$row = mysql_fetch_assoc($q1);
echo $row['browser'];