Ajax - Update database on button click

Question

I need some help with a project. I'm still learning javascript and jquery so bear with me. The website that I'm working on needs to update a database entry when a button is clicked, the button content is also queried from the database.

First database query to get the buttons:

<?php
    $freq_sql = "SELECT freq FROM disc_freq WHERE in_use='0'";
    $result_freq = $connection->query($freq_sql);
    echo "<h5>Available frequencies</h5>";
    while($row = mysqli_fetch_array($result_freq)){
        $set_freq=$row[0];
?>
<a id='button' class='w3-bar-item w3-button'><?php echo $set_freq ?></a>

Then the ajax script I tried but there is something wrong with it

$(document).ready(function(){
    $("#button").click(function(){
        $.ajax({
            url: "set_freq.php",
            type: "POST",
            data: {"set_freq":<?php echo $set_freq ?>}, 
            success: function(data){
                data = JSON.toString(data);

            }
        });
    });
});

Finally the php file

<?php
session_start();
include("konf.php");  
if(isSet($_POST['set_freq'])){ 
    $update_sql="UPDATE disc_freq SET in_use = '1', working_usr='".$_SESSION['username']."' WHERE freq='".$_POST['ins_freq']."'";
    $update_run=mysqli_query($connection,$update_sql);  
}  
?>

For some the first button when clicked on initiates same number ajax calls of how many buttons have been displayed. Others won't do anything.

The php code does work but the only problem is the ajax call and I haven't found a solution yet so any help is appreciated.

Answer 1

please update code as in your code there is error in ajax script in js change you can change code from

  data: {"set_freq":<?php echo $set_freq ?>},

to

   data: {"set_freq":'<?php echo $set_freq ?>'},