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Button to change value in SQL without any redirection

Trying to use Javascript to pass the value from a button
to execute a PHP Script (The script simply changed a boolean column to 1 / True.
However i cannot get the code to work, i am not sure if its my Formatting, but i am not very familiar with Javascript
i am simply trying to change the value in the SQL Database on a column without any redirection.
index.php
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script language="javascript">
$("body").on("click","button", function(ev){
ev.preventDefault(); // prevent submitting a form ...
let data={id: $(this).data("id")}
$.post("viewed.php",data)
.done(function (result) {
console.log("Message:",result);
});
});
</script>
My Button index.php
<div><button name="Delete" data-id='<?echo $data['orderReference']?>'">Delete</button></div>
and Viewed.php
$orderID = $_POST['id'] ;
if ($_POST)
{
try {
$sqlOrderviewed = "UPDATE `Order_Header` SET `orderViewed` = '1' WHERE `Order_Header`.`orderReference` IN ($orderID) ";
$resultOrderupdate = $products->conn->query($sqlOrderviewed); // Execute Statement
echo $count = $resultOrderupdate->rowCount();
} catch
(PDOException $e) { // If error in SQL
echo "One or more errors occurred saving to database This transaction will be rolled back:" . $e->getMessage(); // Display Message on End Point
// $products->conn->rollback(); // Rollback SQL
}
}
I am aware of the SQL Injection in this example, this is not production just trying to get an example working

To do this I would suggest making REST API type behaviour in your PHP that accepts JSON (as an example) which you can define with headers. So your JavaScript can stay mostly the same, just make sure you are pointing to the correct URL. But I think your PHP should look more like this:
<?php
// Headers
header('Access-Control-Allow-Origin: *');
header('Content-Type: application/json');
header('Access-Control-Allow-Methods: POST'); //maybe make this an update to be Semantic with the SQL operation you are doing
// Get raw data from the post you made in JavaScript
$data = json_decode(file_get_contents("php://input"));
$id = $data.id;
// Use the data in your SQL
$sqlOrderviewed = "UPDATE `Order_Header` SET `orderViewed` = '1' WHERE `Order_Header`.`orderReference` IN ($id) ";
?>
If you need more information on creating APIs with PHP I suggest these resources:
https://www.youtube.com/watch?v=OEWXbpUMODk
https://shareurcodes.com/blog/creating%20a%20simple%20rest%20api%20in%20php
https://github.com/bradtraversy/php_rest_myblog
I am not sure that $(this).data("id") is getting the data you want. I assume you want to get the value of data-id in your button? If so I would change your JavaScript to something more like this:
<script language="javascript">
$("body").on("click","button", function(ev){
ev.preventDefault(); // prevent submitting a form ...
let id = ev.target.getAttribute("data-id");
let data={id: id};
$.post("http://localhost:{port}/viewed.php",data)
.done(function (result) {
console.log("Message:",result);
});
});
</script>
I hope this helps!
P.S this is how I might have written the JS for this, I just find it a bit more readable (Not tested, just written in the MD editor while answering the question):
let buttons = document.querySelectorAll("button");
buttons.forEach((button) => {
button.addEventListener("click", (e) => {
e.preventDefault();
let id = e.target.getAttribute("data-id");
let data = {
id: id
};
$.ajax({
type: 'POST',
url: '/viewed.php',
data: data,
success: function(result){
console.log( "result: " + result );
}
})
})
});

How to bring a json result into PHP

I have some results from a fetch.php using json and I successfully brought all results to my bootstrap modal HTML screen.
When the Modal is being shown, I would like to run a MYSQL query using a value coming from the same json I used for the modal, however I can't put this value into a PHP variable to run the SQL query.
How can I get this?
I am trying to bring the same value I input into the HTML textbox (modal), but it is not working. I also tried to use the value from json '$('#PCR').val(data.PCRNo);)', but nothing happen.
This is the script to collect information from database using fetch.php file:
<script>
$(document).ready(function(){
$('#table').on('click', '.fetch_data', function(){
var pcr_number = $(this).attr('id');
$.ajax({
url:'fetch.php',
method:'post',
data:{pcr_number:pcr_number},
dataType:"json",
success:function(data){
$('#PCR').val(data.PCRNo);
$('#PCC').val(data.PCC);
$('#PCR_Creation').val(data.Creation_Date);
$('#PCR_Status').val(data.Stage);
$('#Required_Completion').val(data.Required_Completion);
}
});
});
});
</script>
This is the PHP code
<?php
//trying to get the value I have included on #PCR (textbox) which has ID='PCR' and name ='PCR' **
$PCR= $_POST['PCR'];
//running now the code to check if the database has the value and return the desired response to be shown **
$sql1 = mysqli_query($dbConnected,"SELECT * FROM change_management.tPCN");
while ($row1 = mysqli_fetch_array($sql1)) {
if ($row1['PCRNo']==$PCR){
echo $row1['PCNNo'];
echo "<br/>";
}else{
}
}
?>
I would like include value from this val(data.PCRNo) json return into the $PCR variable, so the MYSQL query is going to work

There are a number of quite basic logical issues with your code which are preventing it from working.
1) data: { pcr_number: pcr_number}- the name pcr_number doesn't match the value PCR which the server is searching for using $_POST['PCR'];. The names must match up. When making an AJAX request, the name you gave to the form field in the HTML does not matter (unless you use .serialize()) because you are specifying new names in the data parameter.
2) Your SQL query doesn't make sense. You seem to be wanting to read a single row relating to a PCR number, yet your query makes no usage of the input PCR value to try and restrict the results to that row. You need to use a SQL WHERE clause to get it to select only the row with that ID, otherwise you'll fetch all the rows and won't know which one is correct. (Fetching them all and then using an if in a PHP loop to check the correct one is very inefficient.) I wrote you a version which uses the WHERE clause properly, and passes the PCR value to the query securely using prepared statements and parameters (to project against SQL injection attacks).
3) Your output from the PHP also makes no sense. You've told jQuery (via dataType: "json" to expect a JSON response, and then your code inside the "success" function is based on the assumption you'll receive a single object containing all the fields from the table. But echo $row1['PCNNo']; echo "<br/>"; only outputs one field, and it outputs it with HTML next to it. This is not JSON, it's not even close to being JSON. You need to output the whole row, and then use json_encode() function to turn the object into a JSON string which jQuery can parse when it receives it.
Here's a version of the code containing all the above changes:
JavaScript:
$(document).ready(function(){
$('#table').on('click', '.fetch_data', function(){
$.ajax({
url: 'fetch.php',
method: 'post',
data: { pcr: $(this).attr('id'); },
dataType: "json",
success: function(data){
$('#PCR').val(data.PCRNo);
$('#PCC').val(data.PCC);
$('#PCR_Creation').val(data.Creation_Date);
$('#PCR_Status').val(data.Stage);
$('#Required_Completion').val(data.Required_Completion);
}
});
});
});
PHP:
<?php
$PCR = $_POST['pcr'];
$stmt = $dbConnected->prepare("SELECT * FROM change_management.tPCN WHERE PCRNo = ?");
$stmt->bind_param('s', $PCR);
$stmt->execute();
$result = $stmt->get_result();
//an "if" here will cause a single row to be read
if ($row = $result->fetch_assoc()) {
$output = $row;
}
else
{
$output = new StdClass();
}
$stmt->free_result();
$stmt->close();
//output the result
echo json_encode($output);
?>
N.B. I would potentially suggest studying some tutorials on this kind of subject, since this is a fairly standard use case for AJAX/JSON, and you should be able to find samples which would improve your understanding of all the different parts.
P.S. Currently the PHP code above will return an empty object if there is no matching row in the database. However, this is probably an error condition (and will cause your JavaScript code to crash due to trying to read nonexistent properties), so you should consider how you want to handle such an error and what response to return (e.g. 400, or 404, and a suitable message).

You need to first return json from php by using json_encode.
Inside this loop
while ($row1 = mysqli_fetch_array($sql1)) {
$data = array('PCRNo' => 'itsvalue', 'PCC' => 'itsvalue', 'Creation_Date' => 'itsvalue')
}
print json_encode($data)
store all the data in an associative array and then convert it into json using json_encode and return the json.
Use json data in you ajax file
$.ajax({
url:'fetch.php',
method:'post',
data:{pcr_number:pcr_number},
dataType:"json",
success:function(data){
var data = JSON.parse(data);
$('#PCR').val(data.PCRNo);
$('#PCC').val(data.PCC);
$('#PCR_Creation').val(data.Creation_Date);
$('#PCR_Status').val(data.Stage);
$('#Required_Completion').val(data.Required_Completion);
}
});

Below is the changed script to store different values in $PCR variable
<script>
$(document).ready(function(){
var i = 1;
$('#table').on('click', '.fetch_data', function(){
if(i == 1) {
var pcr_number = $(this).attr('id');
} else {
var pcr_number = $('#PCR').val();
}
$.ajax({
url:'fetch.php',
method:'post',
data:{pcr_number:pcr_number},
dataType:"json",
success:function(data){
$('#PCR').val(data.PCRNo);
$('#PCC').val(data.PCC);
$('#PCR_Creation').val(data.Creation_Date);
$('#PCR_Status').val(data.Stage);
$('#Required_Completion').val(data.Required_Completion);
i++;
}
});
});
});
</script>

Getting undefined on my Ajax call

I'm getting undefined in the console when trying to log the "data.billAmount" statement. Why is this happening and how do I fix it?
I tried doing JSON.parse and JSON.stringify but those didn't work. I tried using dataType: 'json' but that didn't work. I'm not sure what else to try. I'm stuck.
PHP:
if (#$_POST['action'] == 'addBill')
{
$billName = $_POST['bill_name'];
$billAmount = intval($_POST['bill_amount']);
$data = array(
'billName' => $billName,
'billAmount' => $billAmount,
);
echo json_encode($data);
$stmt = $db->prepare("INSERT INTO bills (billName, billAmount) VALUES(?,?)");
$stmt->bindParam(1, $billName);
$stmt->bindParam(2, $billAmount);
$stmt->execute();
}
JavaScript:
$(".addBill").on("click", function(e) {
e.preventDefault();
var billAmount = $('.billAmount').val();
var billName = $('.billName').val();
$.ajax({
type: "POST",
url: "index.php",
data: {
billAmount: billAmount,
billName: billName,
action: 'addBill'
},
success: function(data) {
console.log(data.billAmount);
}
});
});

Suggest you to move functionality which is responsible for adding bill into separate file. Then make AJAX call to that file and everything would works well, because if you want a particular value point request to particular file which echo that value for you...
No needs to looking for workaround when that could be done in clear and right way by separating functionality into smaller junks.
In case if you insist to use index.php
after
$stmt->execute();
put one more line
exit();
As Mohamed-Yousef commented on question.

Is this piece of jquery ajax code correct?

I am making a simple web chat application using ajax,php,javascript and mysql.
What I am trying to do here is to avoid fetching the whole database after an interval of 1 sec(which is normally done in basic chat application ) but rather I want to fetch and display(by appending) also those chats which have been newly entered into the database by any user.
To implement this ,First when the user first opens the chat screen the whole database is loaded in the chat window(not shown in this code snippet),and then I am using the variable msgid to fetch the latest value of MSg_ID (which is the auto-increment primary key in my chat table) through an ajax request to the page 'Msg.php' which returns the required value of msg_id.
Now using this value of msgid and comparing it with the max value of Msg_ID every second in the database through the ajax request to the page 'Chat3.php'.
If the Max value of Msg_ID has changed the required rows are returned . After this I m updating the value of 'msgid' using the same earlier ajax request to the page 'Msg.php'
The pages Msg.php and Chat3.php are working perfectly ,as I have tested them thoroughly.
My question here is what is the problem in my code , why is not working?
Can we use an ajax request inside a ajax call back function or not?
What else can be a probable source of error?
Any input will be valuable :)
If you have any problem in understanding the code,leave a comment.
'#yyy' and '#zzz' are random div elements which i am using to test the data value of ajax callback function.
I can even post the rest of the code if it helps.
<script type"text/javascript">
$(document).ready(function() {
var dept = '<?php echo $deptId; ?>';
$.ajax({
url: 'scripts/php/Msg.php',
data: {dept:dept},
success: function(data) {
$('#yyy').html(data);//this displays the correct value
var msgid=data;
}
});
var interval = setInterval(function() {
$.ajax({
url: 'scripts/php/Chat3.php',
data: {dept:dept,msgid:msgid},
success: function(data) {
if(data!='bad'){
//$('#messages').prepend(data);
$('#zzz').html(data);//does not display any value although Chat3.php is returning the correct value.
//below ajax request to update the value of msgid
$.ajax({
url: 'scripts/php/Msg.php',
data: {dept:dept},
success: function(data) {
var msgid=data;
$('#zzz').html(data); //not displaying anything although above one is was displaying
}
});
}
}
});
}, 1000);
});
</script>
Here is my Msg.php
<?php
require '../../includes/database/connect.db.php';
function get_msg($dept){
$query= "SELECT Msg_ID,Sender, Message ,Time_stamp FROM chat WHERE Dept_ID='$dept' ORDER BY Msg_ID DESC" ;
$run=mysql_query($query);
$messages =array();
while($message=mysql_fetch_assoc($run)){
$messages[] =array('msgid'=>$message['Msg_ID'],
'sender'=>$message['Sender'],
'message'=>$message['Message'],
'time_stamp'=>$message['Time_stamp']);
}
return $messages;
}
$dept=$_GET['dept'];
$messages = get_msg($dept);
$x=count($messages);
if($x){
foreach($messages as $message) {
if($x==count($messages)){
echo $message['msgid'];
}
$x--;
}
}
?>
Here is my Chat3.php
<?php
require '../../includes/database/connect.db.php';
function get_msg($dept,$msgid){
$query1= "SELECT MAX(Msg_ID) as msg_id FROM chat" ;
$run1=mysql_query($query1);
$row = mysql_fetch_assoc($run1);
$result =$row['msg_id'];
$messages =array();
if($result>$msgid)
{
$query= "SELECT Sender, Message ,Time_stamp FROM chat WHERE Dept_ID='$dept' AND Msg_ID>'$msgid' ORDER BY Msg_ID DESC" ;
$run=mysql_query($query);
while($message=mysql_fetch_assoc($run)){
$messages[] =array('sender'=>$message['Sender'],
'message'=>$message['Message'],
'time_stamp'=>$message['Time_stamp']);
}
return $messages;
}
else
{
return $messages;
}
}
$dept=$_GET['dept'];
$msgid=$_GET['msgid'];
$messages = get_msg($dept,$msgid);
if(count($messages)){
foreach($messages as $message) {
echo '<strong>'.$message['sender'].' Sent</strong><br>';
echo $message['message'].' <i><small><div align="right">'.$message['time_stamp'].'</i></small></div>';
}
}
else {
echo 'bad';
}
?>

The problem is the msgid
In your first AJAX Request you are setting the variable var msgid=data; which is in local scope.
I think you are trying to access that variable in the second AJAX request while sending the datas
url: 'scripts/php/Chat3.php',
data: {dept:dept,msgid:msgid}, // Trying to access the local variable of previous ajax request
EDIT:
Try removing the var from var msgid=data; in your first AJAX request. Removing var will make the variable GLOBAL, Although its not good to pollute the global scope, but you can definitely try out this for the time being

A Better way of doing Fade Out with PHP

I amc creating A Login script with php and javascript.
What I want to do is log the user in without the page refresh which I have archived so far, With some help from Stack Flow users, I am fairly good with PHP but new to the Javascript client side.
Anyway, When the user enters the correct data and the session gets started how do I get it to call the fade out function?
Heres the PHP Side
<?php
require "../core/database.php";
//lets create some veriables to use, This way is shorter
$username = strip_tags(trim($_POST['user_login']));
$password = strip_tags(trim($_POST['pass_login']));
$md5_pass = md5($_POST['pass_login']);
$user_login = mysql_real_escape_string($username);
$pass_login = mysql_real_escape_string($md5_pass);
if (($user_login) && ($password)) {
//Connect to the database to fetch the users username and password
$select_user = mysql_query("SELECT username,password FROM users WHERE username='$user_login' AND password='$pass_login'");
$user_rows = mysql_fetch_array($select_user);
$username_row = $user_rows['username'];
$password_row = $user_rows['password'];
if(($username_row==$user_login) && ($md5_pass==$password_row)) {
//All user information is correct, Now start the session
//I HAVE CALLED IT HERE HOPING THERE,S A BETTER WAY OF DOING THIS. IT WILL CAL
echo "
Yes, Now we can start the session right here, when your ready.
<script>
$('#field').fadeOut();
</script>";
} else {
echo "The username or password you entered is incorrect";
}
} else {
echo "<b>Blank Fields</b> <br>
You must enter A Username/Password Combination";
}
?>
Incase yous need it, there is the client side aswill (modified by some users to make the functionality better)
$(document).ready(function() {
// Make a function that returns the data, then call it whenever you
// need the current values
function getData() {
return {
user_login: $('#user_login').val(),
pass_login: $('#pass_login').val()
}
}
function loading(e) {
$('#content').html('Loading Data');
}
function check(e) {
e.preventDefault();
$.ajax({
url: 'ajax/check.php',
type: 'post',
data: getData(), // get current values
success: function (data) {
$('#content').html(data);
}
});
}
// Don't repeat so much; use the same function for both handlers
$('#field').keyup(function(e) {
if (e.keyCode == 13) {
var username = $('#user_login').val();
loading(e);
check(e);
}
});
$('#submit').click(function(e) {
if (e.keyCode != 13) {
loading(e);
check(e);
}
});
});
Since PHP is Server Side and Java Script controls the Client side, Probably the best way to do or call it is this way, But its worth A ask anyway.
Besides this everything is working out well.
If you want you can help change the way loading data is coded/works, But the functionality is working perfectly so theres not much need.

The ajax success method needs to check the response from the server to see if login was successful and then take the appropriate action:
// php
if(($username_row==$user_login) && ($md5_pass==$password_row)) {
//All user information is correct, Now start the session
echo 'correct';
} else {
echo 'The username or password you entered is incorrect';
}
// js
function check(e) {
e.preventDefault();
$.ajax({
url: 'ajax/check.php',
type: 'post',
data: getData(), // get current values
success: function (data) {
if (data === 'correct') {
$('#field').fadeOut();
} else {
$('#content').html(data);
}
}
});
}

Returning JSON instead of raw HTML is much more flexible. Quick example:
PHP Side
<?php
require "../core/database.php";
$json = array('success' => false, 'error' => null);
$username = strip_tags(trim($_POST['user_login']));
$password = strip_tags(trim($_POST['pass_login']));
$md5_pass = md5($_POST['pass_login']);
$user_login = mysql_real_escape_string($username);
$pass_login = mysql_real_escape_string($md5_pass);
if (($user_login) && ($password)) {
$select_user = mysql_query("SELECT username,password FROM users WHERE username='$user_login' AND password='$pass_login'");
$user_rows = mysql_fetch_array($select_user);
$username_row = $user_rows['username'];
$password_row = $user_rows['password'];
if(($username_row==$user_login) && ($md5_pass==$password_row)) {
$json['success'] = true;
}
else {
$json['error'] = "The username or password you entered is incorrect";
}
} else {
$json['error'] = "<b>Blank Fields</b> <br>You must enter A Username/Password Combination";
}
echo json_encode($json);
Your AJAX function:
function check(e) {
e.preventDefault();
$.ajax({
url: 'ajax/check.php',
type: 'post',
data: getData(), // get current values
success: function (data) {
var loginResult = JSON.parse(data);
if(loginResult.success){
//Login successful - fade out whatever form or fields
//that you want to
$('#field').fadeOut();
} else{
//Add error message to an error div or whatever
$('#error').html(loginResult.error);
}
}
});
}

I'll start by saying that your PHP should be using the newer mysqli_* functions or the PDO object for all of your database queries. Further, you should be using prepared statements which will safeguard you against SQL injection attacks.
Another thing to note is that in a PHP file that is not going to output anything to the browser, or in other words, is just going to run some code, you don't need a closing tag. In fact, you don't want a closing tag. That is because anything after the closing tag will get sent to the browser, which will get included in the response of your AJAX success function. That includes things like spaces and new lines.
Now, on to your PHP. You are going to want to output some JSON so that you can check for success or failure in your AJAX.
PHP
<?php
require "../core/database.php";
//lets create some veriables to use, This way is shorter
$username = strip_tags(trim($_POST['user_login']));
$password = strip_tags(trim($_POST['pass_login']));
$md5_pass = md5($_POST['pass_login']);
$user_login = mysql_real_escape_string($username);
$pass_login = mysql_real_escape_string($md5_pass);
//Create an array to represent our JSON data.
$json = array(
"successCode" => 0
);
if (($user_login) && ($password)) {
//Connect to the database to fetch the users username and password
$select_user = mysql_query("SELECT username,password FROM users WHERE username='$user_login' AND password='$pass_login'");
$user_rows = mysql_fetch_array($select_user);
$username_row = $user_rows['username'];
$password_row = $user_rows['password'];
if(($username_row==$user_login) && ($md5_pass==$password_row)) {
//All user information is correct, Now start the session
//echo "Yes, Now we can start the session right here, when your ready."
$json['successCode'] = 0;
} else {
//echo "The username or password you entered is incorrect";
$json['successCode'] = 1;
}
} else {
//echo "<b>Blank Fields</b> <br>
//You must enter A Username/Password Combination";
$json['successCode'] = 2;
}
//Set that our content type is JSON
header("Content-type: application/json");
echo json_encode($json); //Convert the PHP array to JSON and echo it as the response.
In our PHP, we have created a $json array which will story the successCode that we will be responding to the client. This will tell the client if the login was a success or failure, and even what type of failure occurred. It will then be up to the client to decide how to display that success or failure to the user. This allows multiple applications to use the same server side source, but display the errors differently if desired.
At the end of the PHP, we have set the header Content-type to specify that we are sending back application/json to the client. Then, we encode the PHP array as JSON, and output it to the response.
jQuery/Javascript
//Let's define different messages depending on what status code we get on the client.
var errorMessages = [
"Yes, Now we can start the session right here, when your ready.",
"The username or password you entered is incorrect",
"<b>Blank Fields</b><br />You must enter A Username/Password Combination"
];
function check(e) {
e.preventDefault();
$.ajax({
url: 'ajax/check.php',
type: 'post',
data: getData(), // get current values
success: function (data) {
//First, make sure that data and data.successCode are defined.
if (data && data.successCode) {
//Here, you are getting back the JSON data from the login call.
$('#content').html(errorMessages[data.successCode]);
//If the successCode is 0, which means it was successful, then we want to fade out the #field div.
if (data.successCode == 0) {
$('#field').fadeOut();
}
} else {
//There must've been a server error. You'd handle that here.
}
}
});
}
Why put the error messages on the client instead of the server? Because it allows you to easily change how the error messages are displayed, without having to touch the server side code. The server just outputs an error code, and the client decides how to handle that code.
The Javascript array, errorMessages, defines the error messages corresponding to their index in the array. The error message at index 0 would correspond to successCode = 0, and so on. If you weren't going to use sequential successCodes, you could use a javascript object to specify keys corresponding to each error code.