How To Stop Form Resubmission On Refresh In Php

If the form is already submitted and the user tries to refresh the webpage then the browser will attempt to resubmit the form.

If you are allowing the user to fill and submit the form for insert data. In this case, if the user refreshes the page then the data is reinserted on the MySQL database table if some action does not perform for preventing it.

In this tutorial, I show you some ways by using which you can avoid the page resubmit.

Prevent page from submit on Refresh in PHP

HTML Form
Redirect the user to another page
Check entry in MySQL Database Table
With AJAX
Conclusion

1. HTML Form

In the example, I am using the following <form> that has 4 input fields and a button.

<form method='post' action=''>   <input type='text' placeholder='Enter username' name='txt_uname' id='txt_uname' ><br/>   <input type='text' placeholder='Enter First name' name='txt_fname' id='txt_fname' ><br/>   <input type='text' placeholder='Enter Last name' name='txt_lname' id='txt_lname' ><br/>   <input type='text' placeholder='Enter email' name='txt_email' id='txt_email' ><br/>   <input type='submit' value='Submit' id='submit' name='submit'> </form>

2. Redirect the user to another page

Simply redirect the user to another page after the form successfully submitted.

Example

<?php  include 'config.php'; // Database connection  if(isset($_POST['submit'])){   $uname = $_POST['txt_uname'];   $fname = $_POST['txt_fname'];   $lname = $_POST['txt_lname'];   $email = $_POST['txt_email'];    // Insert record   $insert_query = "INSERT INTO                   users(username,fname,lname,email)                   VALUES('".$uname."','".$fname."','".$lname."','".$email."')";   mysqli_query($con,$insert_query);    // Redirect to another page   header('location: home.php'); } ?>

3. Check entry in MySQL Database Table

Here, you can do two things –

Check the unique value in a field
Check all submit values in MySQL

Check the unique value in a field

Create a field in your table which only stores unique value e.g. username, email, etc on each page submit. Check the submit value in this field if it's not found then insert the record.

Example

<?php  include 'config.php'; // Database connection  if(isset($_POST['submit'])){   $uname = $_POST['txt_uname'];   $fname = $_POST['txt_fname'];   $lname = $_POST['txt_lname'];   $email = $_POST['txt_email'];    // Check username is exists or not   $query = "SELECT count(*) as allcount FROM users WHERE username='".$uname."'";   $result = mysqli_query($con,$query);   $row = mysqli_fetch_array($result);   $allcount = $row['allcount'];    // insert new record   if($allcount == 0){     $insert_query = "INSERT INTO         users(username,fname,lname,email)         VALUES('".$uname."','".$fname."','".$lname."','".$email."')";     mysqli_query($con,$insert_query);   }   } ?>

Check all submit values in MySQL

You can either check all submitted values that exists in the MySQL database table if not then insert a new record.

Example

<?php  include 'config.php'; // Database connection  if(isset($_POST['submit'])){   $uname = $_POST['txt_uname'];   $fname = $_POST['txt_fname'];   $lname = $_POST['txt_lname'];   $email = $_POST['txt_email'];    // Check username is exists or not   $query = "SELECT count(*) as allcount FROM users            WHERE username='".$uname."' && fname='".$fname."' &&            lname='".$lname."' && email='".$email."'";   $result = mysqli_query($con,$query);   $row = mysqli_fetch_array($result);   $allcount = $row['allcount'];    // insert new record   if($allcount == 0){      $insert_query = "INSERT INTO          users(username,fname,lname,email)          VALUES('".$uname."','".$fname."','".$lname."','".$email."')";      mysqli_query($con,$insert_query);   }   } ?>

4. With AJAX

You can use AJAX to save data and you can either reload the page or not on a successful callback.

PHP (saveData.php)

<?php  include 'config.php'; // Database connection  $uname = $_POST['username']; $fname = $_POST['fname']; $lname = $_POST['lname']; $email = $_POST['email'];  $insert_query = "INSERT INTO                   users(username,fname,lname,email)                   VALUES('".$uname."','".$fname."','".$lname."','".$email."')"; mysqli_query($con,$insert_query); echo 1; ?>

jQuery

$(document).ready(function(){    $("#submit").click(function(){     var username = $("#txt_uname").val();     var fname = $("#txt_fname").val();     var lname = $("#txt_lname").val();     var email = $("#txt_email").val();       $.ajax({        url:'saveData.php',        type:'post',        data:{username:username,fname:fname,lname:lname,email:email},        success:function(response){           location.reload(); // reloading page        }     });     }); });

5. Conclusion

I showed you some of the ways by using it you can prevent the page from resubmitting. You can use any of the methods on your webpage.

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