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how to fetch data from sql server database in php without refreshing the page

I am trying to get some data from the database. I create a function that is located in functions.php file that return a value. On another page, I create a variable and just get that value. I was trying to use the onkey to check the database but then I realize that i need to know the amount of tickets even if they don't type anything.
Here is the function:
function.php
function is_ticket_able($conn){
$query = "select number_of_tickets from [dbo].[TICKETS] " ;
$stmt = sqlsrv_query($conn, $query);
while ($row = sqlsrv_fetch_array($stmt)) {
$amount_of_tickets = $row['number_of_tickets'];
}
return $amount_of_tickets;
}
And, I am trying to check the database (without refreshing the page) and get the value on this page:
application.php
$amount_of_tickets = is_ticket_able($conn);
Then, I just check that $amount_of_tickets is not 0 or 1. Because if is one then some stuff have to change.
I am doing this (inside application.php):
if($amount_of_tickets !=0){
//show the form and let them apply for tickets.
//also
if($amount_of_tickets == 1){
//just let them apply for one ticket.
}
}
EDIT: I saw that AJAX would be the right one to use, but I am so confuse using it.
UPDATE:
function.php
function is_ticket_able($conn){
$query = "select number_of_tickets from [dbo].[TICKETS_LKUP] " ;
$stmt = sqlsrv_query($conn, $query);
while ($row = sqlsrv_fetch_array($stmt)) {
$ticket = $row['number_of_tickets'];
}
return $ticket;
}
application.php
$amount_of_tickets = is_ticket_able($conn);
<script type="text/javascript">
var global_isTicketAble = 0;
checkTicket();
function checkTicket()
{
$.ajax(
{
url: "application.php",
method: 'GET',
dataType: 'text',
async: true,
success: function( text )
{
global_isTicketAble = text;
alert(global_isTicketAble);
if( global_isTicketAble == 0 ){
window.location.replace("http://www.google.com");
}
setTimeout( checkTicket, 5000 ); // check every 5 sec
}
});
}
</script>
So, now the problem is that when I alert(global_isTicketAble); it doesn't alert the value from the database but it does alert everything that is inside application.php...Help plzzz

Server side
Assuming you need to check $amount_of_tickets periodically and this can be computed into application.php, inside that file you'll have
<?php
// $conn is defined and set somewhere
$amount_of_tickets = is_ticket_able($conn);
echo $amount_of_tickets;
exit(0);
?>
This way when the script is invoked with a simple GET request the value is returned in the response as simple text.
Client Side
ajax is the way to go if you want to update information on page without reloading it.
Below is just a simple example (using jQuery) that may be extended to fit your needs.
The code below is a JavaScript snippet. A global is used to store the value (globals should be avoided but it's just for the purpose of the example)
Then a function is invoked and the updated value is fetched from function.php script.
The function -prior termination- schedules itself (with setTimeout) to be re-invoked after a given amount of milliseconds (to repeat the fetch value process).
var global_isTicketAble = 0;
checkTicket();
function checkTicket()
{
$.ajax(
{
url: "application.php",
method: 'GET',
dataType: 'text',
async: true,
success: function( text )
{
global_isTicketAble = text;
// eventually do something here
// with the value just fetched
// (ex. update the data displayed)
setTimeout( checkTicket, 5000 ); // check every 5 sec
}
}
}
Note that $.ajax() sends the request but does not wait for the response (as async is set to true). When the request is received the function specified as success is executed.
Complete jQuery ajax function documentation can be found here
http://api.jquery.com/jquery.ajax/

I assume that you have a page (application.php) that displays a table somewhere.
And that you wish to fill that table with the data found in you database.
I'm not sure about WHEN you want these data to be refreshed.
On button click or periodically (like ervery 5 seconds)... But it doesn't matter for what I explain below.
In application.php:
Assemble all your page as you already know how.
But inside it, somewere, just insert an empty div where your table should show:
<div id="dynamicContent"></div>
Also add this script at the bottom of the page:
<script>
function getData(){
PostData="";
$.ajax({
type: "POST",
url: "function.php",
data: PostData,
cache: true,
success: function(html){
$(Destination).html(html);
}
});
}
getData(); // Trigger it on first page load !
</script>
There is 2 variables here... I named it "PostData" and "Destination".
About PostData:
You can pass data collected on the client side to your PHP function if needed.
Suppose you'd need to pass your user's first and last name, You'd define PostData like this:
Fname=$("#Fname").val(); // user inputs
Lname=$("#Lname").val();
PostData="Fname="+Fname+"&Lname="+Lname;
In your function.php, you will retreive it like this (like any normal POST data):
$Fname=$_POST['Fname'];
$Lname=$_POST['Lname'];
If you do not need to pass data from your client side script to you server side PHP... Just define it empty.
PostData="";
Then, about Destination:
This is the place for the empty "dynamic div" id ( I named it "dynamicContent" above).
Don't forget about the hashtag (#) for an id or the dot for a class.
This is a jQuery selector.
So here, PostData would be defined like this:
Destination="#dynamicContent";
The result of the ajax request will land into that "dynamic div".
This WILL be the result of what's defined in function.php..
So, if you follow me, you have to build your table in function.php...
I mean the part where you do your database query and your while fetch.
echo "<table>";
echo "<tr><th>column title 1</th><th>column title 2</th></tr>"
while ($row = sqlsrv_fetch_array($stmt)){
echo "<tr><td>" . $row['data1'] . "</td><td>" . $row['data2'] . "</td></tr>";
}
echo "</table>";
So if you have no data, the table will be empty.
You'll only get the table and table headers... But no row.
There is then no need for a function that checks if there is data or not.
Finally... About the trigger to refresh:
In application.php, you may place a button that fires getData()... Or you may define a setInterval.
It's up to you.
This is how I use ajax to refresh part of a page without reloading it completly.
Since ajax is new to you, I hope this answer will help.
;)
------------------------
EDIT based on Ariel's comment (2016-05-01)
Okay, I understand! Try this:
In application.php:
<div id="dynamicDiv"></div>
<script type="text/javascript">
// timer to trigger the function every seconds
var checkInterval = setInterval(function(){
checkTicket();
},1000);
function checkTicket(){
$.ajax({
type: "POST",
url: "function.php",
data: "",
cache: true,
success: function(html){
$("#dynamicDiv").html(html);
}
});
}
function noMoreTikets(){
clearInterval(checkInterval);
window.location.replace("http://www.google.com");
}
</script>
In function.php:
// Remove the "function is_ticket_able($conn){" function wrapper.
// Define $conn... Or include the file where it is defined.
// I assume that your query lookup works.
$query = "select number_of_tickets from [dbo].[TICKETS_LKUP] " ;
$stmt = sqlsrv_query($conn, $query);
while ($row = sqlsrv_fetch_array($stmt)) {
$ticket = $row['number_of_tickets'];
}
// Add this instead of a return.
if($ticket>0){
echo "There is still some tickets!"; // Text that will show in "dynamicDiv"
}else{
?>
<script>
$(document).ready(function(){
noMoreTikets();
});
</script>
<?php
}
Remember that your PHP scripts are executed server-side.
That is why your "return $ticket;" wasn't doing anything.
In this ajax way to call function.php, its script is executed alone, like a single page, without any relation with application.php, which was executed long ago.
It produces text (or javascript) to be served to the client.
If you want to pass a PHP variable to the client-side javascript, you have to echo it as javascript.
So here, if the PHP variable $ticket is more than zero, some text saying that there is still tickets available will show in "dynamicDiv" and the application page will not be refreshed. I suppose it shows a button or something that allows students to get a ticket.
Else, it will be the javascript trigger to "noMoreTikets()" that will land in the "dynamicDiv".

Jquery error in reloading javascript function trying to load json data with AJAX

I am trying to visualise a folder structure with javascript and json. It automatically loads the root of the folder. When a user clicks on a folder, it should load the files and folder in that folder etc.
The javascript code to get deeper in the json works fine, it loads the first "layer" of the json file with the variable "root". If I change this manually to "roots.deeperFolder" it reaches that folder. That's works fine.
$.ajax({
type: 'GET',
url: 'directory.json',
data: {
get_param: 'value'
},dataType: 'json',
success: buildRoot
});
Code for ajax reaquest and call buildRoot function if succes.
function buildRoot(root, clickedFolder){
if (typeof root === 'string') {
var addFolder = "." + clickedFolder;
var stringRoot = root + addFolder;
var root = eval(stringRoot);
console.log(stringRoot);
}
$.each(root, function(index, element){
if (isNaN(index)) {
$("#sideFolderContainer").append("<li class='folder' id=" + index + ">" + index + "</li>");
}
else {
$("#sideFolderContainer").append("<li>" + element + "</li>");
}
});
}
This function succesfully iterates through the first layer of the JSON file. The "if string" function only applies after click function.
$(document).on('click', '.folder', function(e) {
var root = "root";
var clickedFolder = $(this).attr("id");
buildRoot(root, clickedFolder);
});
This function sends the "deeper folder" information to the previous buildRoot function. The buildRoot function adds the name of the deeper folder to root. (root.deeperFolder) what manually works.
I guess passing through the data between the function is not the problem since this works fine. I get the errors at this line:
$.each(root, function(index, element){
This is what the console outputs (ignore first line).
Link to JSON data.
http://codebeautify.org/jsonviewer/f56dce

I do recommend to use JSON.parse(jsonString); instead of eval.
I thing this is a better approach. (see the jQuery documentation)

Javascript get current page html (after editing)

I have a page that I have edited after load and what I want to do is get the pages current HTML and pass that off to a PHP script.
I first passed document.documentElement.innerHTML but that ended up including a bunch of computed style garbage at the top which I did not want. After googling around I found I could use ajax to get a copy of the current file on the server and then replace the edited part afterwards.
I can get the copy of the file using this:
var url = window.location.pathname;
var filename = url.substring(url.lastIndexOf('/')+1);
$.ajax({
url: filename,
async: false, // asynchronous request? (synchronous requests are discouraged...)
cache: false, // with this, you can force the browser to not make cache of the retrieved data
dataType: "text", // jQuery will infer this, but you can set explicitly
success: function( data, textStatus, jqXHR ) {
origPage = data; // can be a global variable too...
// process the content...
}
});
Which works fine and gets me the html I expected and see when viewing the page in notepad.
The next step is what I cannot figure out. All I want to do is swap out the innerHTML of a div with an id of 'editor' with what the current value is, so I have tried this:
origPage.getElementById('editor').innerHTML = e.html;
But I get the error "TypeError: undefined is not a function". I must be doing something simple wrong I feel but I don't know the proper formatting to do this. I have tried the following variations:
alert($(origPage).getElementById('editor').innerHTML);
//Different attempt
var newHtml = $.parseHTML( origPage );
alert($(newHtml).getElementById('editor').innerHTML);
//Different attempt
alert($(origPage).html().getElementById('editor').innerHTML);
But I always get "TypeError: undefined is not a function" or "TypeError: Cannot read property 'getElementById' of undefined". How can I do this properly?
EDIT:
Complete page html below:
<!DOCTYPE html>
<html>
<body>
<div id="editor">
<h1>This is editable.</h1>
<p>Click me to start editing.</p>
</div>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script type="text/javascript" src="snapeditor.js"></script>
<script type="text/javascript">
var editor = new SnapEditor.InPlace("editor", {onSave: function (e) {
var isSuccess = true;
//var origPage = e.html;
var origPage;
var url = window.location.pathname;
var filename = url.substring(url.lastIndexOf('/')+1);
// Actually perform the save and update isSuccess.
// Javascript:
$.ajax({
url: filename,
async: false, // asynchronous request? (synchronous requests are discouraged...)
cache: false, // with this, you can force the browser to not make cache of the retrieved data
dataType: "text", // jQuery will infer this, but you can set explicitly
success: function( data, textStatus, jqXHR ) {
origPage = data; // can be a global variable too...
// process the content...
}
});
//origPage shows expected html as this point
//alert($(origPage).getElementById('editor').innerHTML);
//alert($(origPage).html().getElementById('editor').innerHTML);
$(origPage).getElementById('editor').innerHTML = e.html;//fails here
alert(origPage);
//alert(newHtml.getElementById('editor').innerHTML);
$.ajax({
data: {html: origPage, docName: 'example1.html'},
url: 'savePage.php',
method: 'POST', // or GET
success: function(msg) {
alert(msg);
isSuccess = true;
}
});
return isSuccess || "Error";
},
onUnsavedChanges: function (e) {
if(confirm("Save changes?")) {
if(e.api.execAction("save")){
//location.reload();
}
} else {
e.api.execAction("discard");
}
}});
</script>
</body>
</html>

It seems that you get the user's changes in a variable - you called the var e.html. That is not a good variable name, BTW. If you can, change it to something like htmlEdited
Question: If you add the command alert(e.html); what do you get? Do you see the HTML after user edits?
If yes, then what you need to do is send that variable to a PHP file, which will receive the data and stick it into the database.
Code to send the data:
javascript/jQuery:
alert(e.html); //you should see the user-edited HTML
$.ajax({
type: 'post',
url: 'another_php_file.php',
data: 'userStuff=' + e.html, //var_name = var_contents
success: function(d){
window.location.href = ''; //redisplay this page
}
});
another_php_file.php:
<?php
$user_edits = $_POST['userStuff']; //note exact same name as data statement above
mysql_query("UPDATE `your_table_name` SET `your_col_name` = '$user_edits' ") or die(mysql_error());
echo 'All donarino';
The AJAX javascript code will send the var contents to a PHP file called another_php_file.php.
The data is received as $user_edits, and then inserted into your MySQL db
Finally, I presume that if you redisplay that page it will once again grab the contents of the #editor div from the database?
This is where you haven't provided enough information, and why I wanted to see all your code.
ARE you populating that div from the database? If not, then how do you expect the page to be updated after refreshing the page?
You would benefit from doing some tutorials at phpacademy.org or a thenewboston.com. Do these two (free) courses and you'll be an expert:
https://phpacademy.org/videos/php-and-mysql-with-mysqli
https://phpacademy.org/videos/oop-loginregister-system
If all you need to do is insert the contents of e.html to replace the #editor div, then try this:
$('#editor').html(e.html);
HOWEVER, you need an event to trigger that code. Are you able to do this?
alert(e.html);
If so, then put the first bit of code at that same spot. If not, we need more information about when your code receives that variable -- that is where you put the $('#editor').html(e.html); statement.

how to use AJAX?

I'm trying to use AJAX so that you don't see the reload refresh.
i want if i change the select button from 1 to 5 that you can see 5 live change and that i can use the 5 in a php variable.
i got this:
<script>
$(document).on('change', '#hoeveelheid', function(e) {
var j_Hoeveelheid = this.options[e.target.selectedIndex].text;
$.ajax({
type: 'POST',
url: 'do.php',
data: {aantal : j_Hoeveelheid},
success: function (data) {
$('.test').html(data);
}
});
}
</script>
Now is my question what i need to set in the do.php file?
so that my script works without any refresh visible.

what i need to set in the do.php file?
At php file you are sending this object:
data: {aantal : j_Hoeveelheid},
so you need to get the key aantal at php end.
You can do this in your php file:
<?php
$aantal = $_POST['aantal'];
echo $aantal . " is the posted value of dropdown.";
?>

Ajax POST is not posting onclick to current page

Alright so this has been bugging me for a long time now... I have tried everything but I cant get it to work!
So what I want to have is a link that acts as a button, and once you click it, it POSTs an ID number of the button in the form "{ 'id' : id }"
edit-homepage.php:
<script>
$(function() { // document ready
$('a.inactive').on('click', function(event) {
event.preventDefault(); // instad of return false
var id = $(this).data('id');
// use $.post shorthand instead of $.ajax
$.post('edit-homepage.php', {id: id}, function(response) {
// after you get response from server
editSlide(id);
});
});
});
</script>
The a href button is created using PHP and I want it to call the ajax function postID( id ) which will post the id so that later I can populate a form via PHP using the posted id.
edit-homepage.php:
echo '<li><a class="inactive" id="slide-'.$info["id"].
'" onClick="postID('.$info["id"].'); editSlide('.$info["id"].'); return false;">'
.'<img src="../images/'.$info["img"].'" width="175"/><p>Edit Slide '
. $info["id"] .'</p></a></li>';
Currently, when I click the link, it opens the alert but it is EMPTY or Undefined. It is supposed to display "ID: 1" for example if the link clicked has a ID of 1.
edit-homepage.php:
<script>
function editSlide($id) {
<?PHP
if (isset ($_POST['id'])) {
echo "alert('success!2');";
}$id = !empty($_POST['id']) ? $_POST['id'] : '';
$data = mysql_query("SELECT * FROM slider WHERE id='$id'") or die(mysql_error());
$info = mysql_fetch_array( $data );?>
document.getElementById("edit-slide-id").innerHTML="Edit Slide #"+$id;
document.getElementById("edit-form").style.display = "block";
document.getElementById("short-title").value="<?PHP echo $info['s_title']; ?>";
}
</script>
Thanks!

With jquery, you don't need to use attributes to attach events, like that:
$(function() { // document ready
$('a.inactive').on('click', function(event) {
event.preventDefault(); // instad of return false
var id = $(this).data('id');
// use $.post shorthand instead of $.ajax
$.post('edit-homepage.php', {id: id}, function(response) {
alert('ID:' + response);
// after you get response from server
editSlide(id);
});
});
});
As of server side, try replacing raw
<?PHP echo $_POST['id']; ?>
With
<?php echo !empty($_POST['id']) ? $_POST['id'] : '' ?>
You likely get notice about Undefined index id, which breaks javascript if there is no post data.
UPDATE
edit-homepage.php shold be separated something like that:
if(!empty($_POST)) {
// here you process your post data and return
// only wenever you want to pass to script
// not all the html
} else {
// here you output html and scripts, but don't do request processing
}
You should always remember, that your HTML rendering must always be separated from your logic. It is better to put views in separate files from logic, though it is not required, it is much easier to debug and maintain.

You can not include PHP code that is supposedly to run after the ajax call. The PHP code will be run only to generate the page. Anything you want to include in alert should be provided in the ajax response, in your case the data variable.

You need to use alert('ID: ' + id).
The $_POST['id'] part of the script does not react to the AJAX request. It is whatever the $_POST['id'] value is when the script is output to the browser (i.e. when the page is first loaded).
You will see this if you view the source.

alert ("ID:"+data);
then only you will get response
or
alert("ID"+id);
this will alert the id passes to function

http://jsfiddle.net/U54ME/
$(".checkthisclass").click(function() {
$.ajax({
type: "POST",
url: "edit-homepage.php",
data: { 'id' : $(this).attr("slideid"); },
success: function(data) {
alert(data);
}
});
}
});
--
<ul>
<li><a class="inactive checkthisclass" id="slide-5" slideid = "5" ><img src="http://blog.entelo.com/wp-content/uploads/2013/04/stackoverflow-logo.png" width="175"/><p>Edit Slide 5</p></a></li>
</ul>