Question

This is a follow-up question to this one: Check for specific integer in a row WHERE user = $name

I want a user to be able to comment on my site for exactly five times a day. After this five times, the user has to wait 24 hours.
In order to accomplish that I raise a counter in my MYSQL database, right next to the user.
So where the name of the user is, there is where the counter gets raised. When it reaches 5 it should stop counting and reset after 24 hours. In order to check the time I use a timestamp. I check if the timestamp is older than 24 hours. If that is the case, the counter gets reseted (-5) and the user can comment again. In order to do that, I use the following code, however it never stops at five, my guess is that my comparison is wrong somehow:

$counter = mysql_query("SELECT FROM table VALUES CommentCounterReset WHERE Name = '$name'");

if(!isset($_SESSION['ts'])); {
    $_SESSION['ts'] = time();
}

if  ($counter >= 5) { 
    if (time() - $_SESSION['ts'] <= 60*60*24){
        echo "You already wrote five comments.";
    }
    else {
        $sql = "UPDATE table SET CommentCounterReset = CommentCounterReset-5 WHERE Name = '$name'";   
    }     
}  
else {
 $sql = "UPDATE table SET CommentCounterReset = CommentCounterReset+1 WHERE Name = '$name'";
    echo "Your comment has been added.";
}

Answer 1

You should let him add comments 5 times a day, not after 24 hours:

$db = new PDO('mysql:host=localhost;dbname=test', 'root', '', array(PDO::ATTR_EMULATE_PREPARES => false, PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));

$stmt = $db->prepare("SELECT `Name`, `timestamp`, `CommentCounterReset` FROM `table` WHERE `Name`=:name");
$stmt->execute(array(':name' => $_GET['name']));
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$lastComment = $row['timestamp']; // timestamp from database and not from $_SESSION because $_SESSION get's destroyed.
$countComments = $row['CommentCounterReset']; // number of comments added

$row_count = $stmt->rowCount();
if(!$row_count){
    $stmt = $db->prepare("INSERT INTO `table` VALUES(0, :name, :timestamp, 1)");
    $stmt->execute(array(':name' => $_GET['name'], ':timestamp' => date('U')));
    echo "Your comment has been added.";
} else {
    if($countComments > 4 && date('d') == date('d', $lastComment)){ // if number of comments are greater than 4 and is same day
        echo "You already wrote five comments today.";
    } else {
        if(date('d') != date('d', $lastComment)){ // if there are different days, reset the counter to 1
            $stmt = $db->prepare("UPDATE `table` SET `CommentCounterReset` = 1, `timestamp`=:timestamp WHERE `Name`=:name");
            $stmt->execute(array(':name' => $_GET['name'], ':timestamp' => date('U')));
        } else { // if it's same day increase counter with 1
            $stmt = $db->prepare("UPDATE `table` SET `CommentCounterReset` = `CommentCounterReset`+1 WHERE `Name`=:name");
            $stmt->execute(array(':name' => $_GET['name']));
        }
        echo "Your comment has been added.";
    }
}

for mysql_* but I’m highly discouraging it!

$link = mysql_connect('localhost', 'root', '');
mysql_select_db('test', $link);

$stmt = mysql_query("SELECT `Name`, `timestamp`, `CommentCounterReset` FROM `table` WHERE `Name`='".mysql_real_escape_string($_GET['name'])."'");
$num = mysql_num_rows($stmt);

if(!$num){
    $stmt = mysql_query("INSERT INTO `table` VALUES(0, '".mysql_real_escape_string($_GET['name'])."', '".date('U')."', 1)");
    echo "Your comment has been added.";
} else {
    $row = mysql_fetch_assoc($stmt);
    $lastComment = $row['timestamp']; // timestamp from database and not from $_SESSION because $_SESSION get's destroyed.
    $countComments = $row['CommentCounterReset']; // number of comments added

    if($countComments > 4 && date('d') == date('d', $lastComment)){ // if number of comments are greater than 4 and is same day
        echo "You already wrote five comments today.";
    } else {
        if(date('d') != date('d', $lastComment)){ // if there are different days, reset the counter to 1
            $stmt = mysql_query("UPDATE `table` SET `CommentCounterReset` = 1, `timestamp`='".date('U')."' WHERE `Name`='".mysql_real_escape_string($_GET['name'])."'");
        } else { // if it's same day increase counter with 1
            $stmt = mysql_query("UPDATE `table` SET `CommentCounterReset` = `CommentCounterReset`+1 WHERE `Name`='".mysql_real_escape_string($_GET['name'])."'");
        }
        echo "Your comment has been added.";
    }
}

my table:

CREATE TABLE `table` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `Name` varchar(30) NOT NULL,
  `timestamp` int(11) NOT NULL,
  `CommentCounterReset` int(11) NOT NULL,
  UNIQUE KEY `id` (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;