Bdtjtk

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?

Header the user to a new page :

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')");



}

//best outside the if statement so user isn't stuck on a white blank page.

header("location: landing_page.php");

exit;

By doing this the user who refreshes will be refreshing landing_page.php which means it won't do the insert twice.

best advice: do a check to see if user exists first if so don't insert!

What is going on here is that when you refresh page, the form is submitted twice.

To prevent this, you can use sessions:

session_start();



if( $_SESSION['submit'] == $_POST['submit'] && 

     isset($_SESSION['submit'])){

    // user double submitted 

}

else {

    // user submitted once

    $_SESSION['submit'] = $_POST['submit'];        

} 

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.

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;

}

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');

}

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>';

        }               

?>

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';

 }

The fast way is to redirect the page to it's current location:

if (isset($_POST['submit'])) 

{

//do somthing

header("Location: $current_url");

}