stop inserting data in the database when refreshin

Question

I am looking for a way to stop inserting or sending data in the database when refreshing the page.

here is my code:

user_details_page.php

<form action="confirm_page.php" method="post" >
User Name:  
<input  type="text" name="username" >
User Email
<input  type="text" name="useremail" >
Password:  
<input  type="text" name="password" >
<input type="submit"  name="submit" >
</form>

---

confirm_page.php

if (isset($_POST['submit'])) 
{
$user= $_POST['username'];
$email = $_POST['useremail'];
$pass= $_POST['password']; 

mysql_query("INSERT INTO table (username, useremail, email) VALUES ('$username','$useremail','$email');

}

so the problem everytime I refresh the confirm page.php the data is sent to the database. how to stop this?

Answer 1

i have this solution by using session

<?php session_start();
        if(isset($_POST[$_SESSION[a][count($_SESSION[a])-1]])){
            echo "somthing....";
            unset($_SESSION[a]);
        }
        else{     
                        echo '<form method="post">';
                              $_SESSION["a"]=array();
                              $_SESSION["a"][0]="a".rand(1,100);
                        echo '<input name="'.$_SESSION["a"][0].'"><br>';
                              $_SESSION["a"][1]="a".rand(1,100);
                        echo '<input name="'.$_SESSION["a"][1].'"><br>';
                              $_SESSION["a"][2]="a".rand(1,100);
                        echo '<input name="'.$_SESSION["a"][2].'"><br>';
                              $_SESSION["a"][3]="a".rand(1,100);
                        echo '<input type="submit" name="'.$_SESSION["a"][3].'" value="submit"><br>';
                        echo '</form>';
        }               
?>

Answer 2

if($_POST(submit)
{
 //database insertion query
 // if successful insertion
    {
echo"<script language='javascript'>alert('successfully inserted')</script>";
echo"<script>document.location='your_page.php';</script>;
    }
}

Answer 3

We can stop it without redirect , best way to use PHP $_SESSION like this :

if($_SERVER['REQUEST_METHOD'] == 'POST' && empty($_SESSION['form_submit']) )
{ 
    extract($_POST);
    $sql=""INSERT INTO table (username, useremail, email) VALUES('$username','$useremail','$email')";
    $_SESSION['form_submit']='true'; 
} 
else
 {
    $_SESSION['form_submit']='NULL';
 }

Answer 4

confirm_page.php:

if (isset($_POST['submit'])) 
{
$user= $_POST['username'];
$email = $_POST['useremail'];
$pass= $_POST['password']; 

mysql_query("INSERT INTO table (username, useremail, email) VALUES ('$username','$useremail','$email')"); // <-- missing endquote and bracket here

header('Location: somewhere_else.php');
exit;
}

Answer 5

Once an insert or update is done in your code you always need to redirect to another page.

See here on how to do that: How to make a redirect in PHP?

(You want to use a PHP redirect, not a Javascript or HTML one, because you obviously really need this to work.)

The confirm page should be what you redirect to after the update, not what does the insert.

Answer 6

The best way to prevent that is to add header('Location: filename') after your query. Thus in your case,

if (isset($_POST['submit'])) 
{
$user= $_POST['username'];
$email = $_POST['useremail'];
$pass= $_POST['password']; 

mysql_query("INSERT INTO table (username, useremail, email) VALUES ('$username','$useremail','$email');
//must be inside the condition to prevent too many redirects
header('Location: user_details_page.php');
}