Ajax request not working on button click using PHP and MySQL

Question

I'm sending an ajax request through JavaScript on clicking a button. When button gets clicked a function is called from where ajax request is performed.

Here is the html code where function is called:

echo "
<form > ";
if ($status == 'regular') {
    echo "<input type='hidden' value='".$id."' name='id'>";
     echo "<input type='hidden' value='official' name='status'>";
    echo "<td><button class='btn btn-info' onclick='UpdateStatus(".$id.",'official')'>UPDATE TO OFFICIAL</button><br><br>";
}
if ($status == 'official') {
     echo "<input type='hidden' value='".$id."' name='id'>";
     echo "<input type='hidden' value='regular' name='status'>";
echo "<td><button class='btn btn-success' onclick='UpdateStatus(".$id.",'regular')'>UPDATE TO REGULAR</button><br><br>";
    }
echo "</form>";

UpdateStatus() is the function in which there is ajax request. From here I'm sending $id which is user ID and the status which is to be updated.

Here is the UpdateStatus() function:

<script>
function UpdateStatus(str,str1) {
if (str.length == 0) {
    document.getElementById("txtHint").innerHTML = "";
    return;
} else {
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = function() {
      //ready
    };
    xmlhttp.open("GET", "update_status.php?id=" + str + "&status=" + str1, true);
    xmlhttp.send();
}
}
</script>

The str and str1 are the Id and status respectively. Here is the update_status.php:

<?php
$id = $_REQUEST["id"];
$status = $_REQUEST["status"];
$server_name = "localhost";
$user_name = "root";
$password = "";
$db = "diwan";
$conect = new mysqli($server_name, $user_name, $password, $db);
if($conect->connect_error)
{ die("Connection failed ".$conect->connect_error); }
$sql = "UPDATE user SET status = '$status' WHERE UserID = $id";
if(!$conect->query($sql))
      {echo "error in adding record ".$conect->error;}
$result = $conect->query($sql);
?>

And when I click on button I get url of this format:

http://localhost/diwan_web/manageusers.php?id=2&status=official

But it's not updating the data in database. Please guide me where I'm wrong or if anything is missing. Any suggestion will be highly appreciated.

What is the purpose of "txtHint"? and when you click on update button, do you get the values inside function UpdateStatus(str,str1)? You may use console.log(str,str1); inside function. — Sayem, Oct 13 '19 at 10:32
Yes the values are coming to the function and going to next page, I've also posted the url, you can check it out — Murtaza Ahmad, Oct 13 '19 at 10:52
It is a very bad idea to use `die(mysqli_error($conn));` in your code, because it could potentially leak sensitive information. See this post for more explanation: [mysqli or die, does it have to die?](https://stackoverflow.com/a/15320411/1839439) — Dharman, Oct 13 '19 at 10:52
It's just a sample code for testing few things, I'll avoid these things in projects — Murtaza Ahmad, Oct 13 '19 at 10:55
You are running your update query twice. Once in the `if` and then again to assign the return value to `$result`. — Dave, Oct 13 '19 at 10:57

score 0 · Answer 1 · answered Oct 13 '19 at 10:49

0

Looks like your syntax is wrong. Try $sql = "UPDATE user SET status = ".$status." WHERE UserID = ".$id";

answered Oct 13 '19 at 10:49

Saulius Liausėdas

9

score 0 · Answer 2 · answered Oct 13 '19 at 11:22

0

Code looks good. There is probably an error you are not seeing.

Add this to top:

ini_set('error_reporting', E_ALL);
ini_set('display_errors', true);

answered Oct 13 '19 at 11:22

user12209248

1

Top-Master · Answer 3 · 2019-10-13T11:53:51.440

There were some issues:

You need to ensure the button does not reload the page (with type='button' as mentioned in another post).
We should always use double-quote for HTML attributes to prevent such mistakes (use onclick=\"UpdateStatus('param-here')\" instead of onclick='...')
If you use PHP's double-quote features you do not need to concatenate manually (If PHP finds $ in double-quotes like echo "Variable is: $x" it tries to find and concatenate the $x variable automatically).

If you apply above mentioned changes your code should look like:

echo "<form >";
if ($status == 'regular') {
  echo "<input type='hidden' value='$id' name='id'>";
  echo "<input type='hidden' value='official' name='status'>";
  echo "<td><button type='button' class='btn btn-info' onclick=\"UpdateStatus('$id','official')\">UPDATE TO OFFICIAL</button><br><br>";
}
if ($status == 'official') {
  echo "<input type='hidden' value='$id' name='id'>";
  echo "<input type='hidden' value='regular' name='status'>";
  echo "<td><button type='button' class='btn btn-success' onclick=\"UpdateStatus('$id','regular')\">UPDATE TO REGULAR</button><br><br>";
}
echo "</form>";

Ajax request not working on button click using PHP and MySQL

3 Answers3