Duplication of Data in MySQL?

General PHP Help
#1

Hi everyone!

I got a little problem, but I really have no idea how to solve it. I had to create a little number guessing game and be able to collect data in the databank. My DataBank is very simple. It consists of username, points and time when played. So I don’t have any primary key or things like that. So how can I actually avoid duplications when page is refreshed??? My code is divided to 2 pages, quiz.php output and logic.php. Here they are:

logic.php

[php]<?php
session_start();

$dblink = mysqli_connect(‘localhost’, ‘root’) or die("Cannot select database! " . mysql_error());
$gamedata = mysqli_select_db($dblink, ‘guessgame’);

if (!$gamedata) {
die ('Cannot use DB : '.mysqli_error($dblink));
}

####################################
############— MENU —############
####################################

$title = ‘’;
$content = ‘’;
$menu = $_GET[‘menu’];

if($menu == ‘quiz’) {
$title = ‘Quiz’;
$content = ‘quiz_c.php’;
}elseif($menu == ‘info’){
$title = ‘Info’;
$content = ‘info_c.php’;
}else{
$title = ‘Home’;
$content = ‘home_c.php’;
}

########################################
############— USERNAME —############
########################################

if($_POST[‘formular’] == “username_form”){
if(ctype_alpha($_POST[“username”])==false || strlen($_POST[“username”]) > 20){
echo “Please use only letters of max length 20”;
return false;
} else {
$_SESSION[‘username’] = true;
$_SESSION[‘username’] = $_POST[‘username’];
}
}

####################################
############— GAME —############
####################################

if (empty($_SESSION[‘try_numb’]))
{
$_SESSION[‘try_numb’] = 1;
$_SESSION[‘points’] = 0;
}

	if($_POST['formular'] == "guess_game"){
		if ($_SESSION['try_numb'] < 11){
			$guess = $_POST['guess'];
			$random_num = rand(1, 5);
					if($guess == $random_num){
						$_SESSION['points']++;
					}
				$_SESSION['try_numb']++;
		}
		#else {							
		#}
	}
	
	
	if ($_POST['formular'] == 'new_game'){
		session_destroy();
		session_start();
		unset($_SESSION['username']);
 }

?>[/php]

And the game:

[php]<?php
if($_SESSION[‘username’] == false){
?>

Spielername:






<?php } else { if ($_SESSION['username'] == true && $_SESSION['try_numb'] < 11) { echo "Ihr Spielername: ".$_SESSION['username']."
"; echo "Das ist dein ".$_SESSION['try_numb'].". Versuch!"."
"; echo "Du hast bis jetzt ".$_SESSION['points']." korrekte Antworten!"."
"; ?>

An welche Zahl denke ich jetzt?

<?php } else { $_SESSION['timestamp'] = time(); $time = $_SESSION['timestamp']; $name = $_SESSION['username']; $points = $_SESSION['points']; $sql="INSERT INTO guessgame (name, points, time) VALUES ('$name','$points','$time')"; $result = mysqli_query($dblink,$sql); if ( !$result ) { die('Ups, Fehler: '.mysqli_error($dblink)); } echo "Ihr Spielername: ".$_SESSION['username']."
"; echo "Fertig!"."
"; echo "Du hast ".$_SESSION['points']." korrekte Antworten!"; ?> 
<form method="post">
<input type="submit" name="new_game" value="new game" />
<input type="hidden" name="formular" value="new_game" />
</form>
<?php } } ?>[/php]

I would be sooo greatful if someone could help me with it!!!

#2

simply run and a query to check if what you are inserting already exist.

if it doesnt exist go ahead and insert it

#3

Yeah, I also thought of it. But the problem is that my user can play countless times and each time he starts new. If I refresh page few secs later in the end of game, then it already looks like “new” game, cause timestamp will change. But if I check my DataBank with just a name and points? What if same player plays once again and get same points?

#4

i understand,

i think the only 2 solutions will be check the database before any Insert OR update any records after each game

hopefully other folks here will drop by and give you more advise

#5

Thanks for your advices anyway! :slight_smile:

#6

Any any help?

#7

Yuhu! I did it! :slight_smile: I added in the output (quiz) a new session variable in the end of saving data to mysql and in the logic used header(Location: ‘…’); :slight_smile:

Here is the full code, maybe it will help someone one day. :slight_smile:

The Output (Quiz):
[php]<?php

	if($_SESSION['username'] == false){

?>

Spielername:






<?php } else { if ($_SESSION['username'] == true && $_SESSION['try_numb'] < 11) { echo "Ihr Spielername: ".$_SESSION['username']."
"; echo "Das ist dein ".$_SESSION['try_numb'].". Versuch!"."
"; echo "Du hast bis jetzt ".$_SESSION['points']." korrekte Antworten!"."
"; ?>

An welche Zahl denke ich jetzt?

<?php } else { $_SESSION['timestamp'] = time(); $time = $_SESSION['timestamp'] + 7200; $name = $_SESSION['username']; $points = $_SESSION['points']; $sql="INSERT INTO guessgame (name, points, time) VALUES ('$name','$points','$time')"; $result = mysqli_query($dblink,$sql); if ( !$result ) { die('Ups, Fehler: '.mysqli_error($dblink)); } echo "Ihr Spielername: ".$_SESSION['username']."
"; echo "Fertig!"."
"; echo "Du hast ".$_SESSION['points']." korrekte Antworten!"; $_SESSION['sqldata'] = $sql; ?> 
<form method="post">
<input type="submit" name="new_game" value="new game" />
<input type="hidden" name="formular" value="new_game" />
</form>
<?php } } ?>[/php]

And The Logic:

[php]<?php
session_start();

if(isset($_SESSION[‘sqldata’])){
session_destroy();
header(‘Location: ?menu=quiz’);
exit;

	}

$dblink = mysqli_connect(‘localhost’, ‘root’) or die("Cannot select database! " . mysql_error());
$gamedata = mysqli_select_db($dblink, ‘guessgame’);

if (!$gamedata) {
die ('Cannot use DB : '.mysqli_error($dblink));
}

####################################
############— MENU —############
####################################

$title = ‘’;
$content = ‘’;
$menu = $_GET[‘menu’];

if($menu == ‘quiz’) {
$title = ‘Quiz’;
$content = ‘quiz_c.php’;
}elseif($menu == ‘info’){
$title = ‘Info’;
$content = ‘info_c.php’;
}else{
$title = ‘Home’;
$content = ‘home_c.php’;
}

########################################
############— USERNAME —############
########################################

if($_POST[‘formular’] == “username_form”){
if(ctype_alpha($_POST[“username”])==false || strlen($_POST[“username”]) > 20){
echo “Please use only letters of max length 20”;
return false;
} else {
$_SESSION[‘username’] = true;
$_SESSION[‘username’] = $_POST[‘username’];
}
}

####################################
############— GAME —############
####################################

if (empty($_SESSION[‘try_numb’]))
{
$_SESSION[‘try_numb’] = 1;
$_SESSION[‘points’] = 0;
}

	if($_POST['formular'] == "guess_game"){
		if ($_SESSION['try_numb'] < 11){
			$guess = $_POST['guess'];
			$random_num = rand(1, 5);
					if($guess == $random_num){
						$_SESSION['points']++;
					}
				$_SESSION['try_numb']++;
		}
		#else {						
		#}
	}
	
	
	if ($_POST['formular'] == 'new_game'){
		session_destroy();
		session_start();
		unset($_SESSION['username']);
 }

?>[/php]

Sponsor our Newsletter | Privacy Policy | Terms of Service