Avoid buuton back and page refresh double insertation ??

[Coldman]

I have a big problem with an page, every time a make refresh the data are inserting one more time the same happens with back button, does any one knows how to avoid this big problem, thanks in advance

[pocobueno1388]

In your header file, put this line of code at the top

header("Cache-control: private");

 

 

[Coldman]

where to put that header ?

[pocobueno1388]

Do you have a file that is included at the top of every script you write? That is called the header file. If you don't have one, then your going to have to put this at the top of all your scripts.

[Coldman]

i don't have header file and i putet the code in every script but still not working

 

here it the code

please see what we can do to prevent this problem

<?php

header("Cache-control: private");

session_start();

 

$CartID1= "1";

 

//if($_SESSION['isok']){

 

$_SESSION['cartid']=$CartID1;

$_SESSION['quantity']="1";

$_SESSION['productid']=$_GET['var'];

$_SESSION['productname']=$_GET['var1'];

$_SESSION['price']=$_GET['var2'];

 

 

$productid=$_SESSION['productid'];

$cartid= $_SESSION['cartid'];

$productname=$_SESSION['productname'];

$price=$_SESSION['price'];

$quantity= $_SESSION['quantity'];

 

                                   

 

 

 

 

echo $price;

$con = mysql_connect("localhost","root","");

if (!$con)

  {

  die('Could not connect: ' . mysql_error());

  }

 

 

mysql_select_db("manvisdatabse", $con);

$query  = mysql_query("INSERT INTO cart (CartID,ProductID,ProductName,Price, Quantity, TotalPrice) VALUES ('$cartid',

'$productid', '$productname', '$price', '$quantity', '$price')ON DUPLICATE KEY UPDATE Quantity=Quantity+'$quantity', TotalPrice=Price*Quantity");

 

unset($productid);

unset($cartid);

unset($productname);

unset($price);

unset($quantity);

if(!$query)

{

echo"Query Lesh";

}

 

 

mysql_close($con);

 

 

[Coldman]

Any other idea how to avoid insertation on refresh ?

[Coldman]

header("Cache-control: private");

this works only for back button

[Coldman]

Any help here ?

[pocobueno1388]

I think the only way you can go, is to check if you have that information in the database already, and if you do, give them an error.

 

So once they add the item to the cart and press refresh, instead of adding the item again, it will give them an error saying that the item has already been added.