Update values from MYSQL table without reloading the page? - php

I've build a small login system for a home project,so,when the user do the login,he is redirect to the userspage.php.In the page i get some data from my mysql table,but the problem is,one of the values i fetch is display to the user with a button near it,when the user press those button i need to perform an php action to increase the value which is display with the button(as an example==> myvalue = 10 | When the user clicks on the button: myvalue = 11 ).I've already build this part,it is working perfectly,but i need to increase the value and update the mysql column without refreshing the page?I know its possible but every tutorial from the web i've tried doesn't work.
Thanks is advance!

AJAX is what you're looking for. Best lib for that is jQuery with it's $.ajax() method http://api.jquery.com/jQuery.ajax/

The following code has a button which onclick calls updatedb.php and shows its output in div element called 'result'
<html>
<head>
<script type="text/javascript">
function UpdateDb()
{
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("result").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","updatedb.php",true);
xmlhttp.send();
}
</script>
</head>
<body>
<button onclick='UpdateDb()'>Update</button>
<p> <span id="result"></span></p>
</body>
</html>
Then write updatedb.php
<?php
do mysql update here.
and echo the result you want to display.
?>

Related

Sql Querying with Ajax while offline returning blank

I'll over simplify the problem in order to make it easier. I'm using the following Ajax script to call another .php file and have it return the results to the original page. I'm using Apache offline and the page is unfortunately returning blank.
<html>
<head>
<script>
function showInfo(str) {
var xmlhttp;
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status== 200) {
document.getElementById("result").innerHTML= xmlhttp.responseText;
}
}
xmlhttp.open("GET","practice.php?q="+str,true);
xmlhttp.send();
}
window.onload = function() { showInfo('bleh'); };
</script>
</head>
<body>
<div id="result"></div>
</body>
//Then the code below is another file called practice.php, which corresponds the ajax above
<?
$test = $_GET['q'];
echo $test;
?>
I am pretty sure $_GET is a case-sensitive variable name on most OSes, so $_Get would be empty.
I would comment if I could -
What happens when you try to hit the page directly (ie put practice.php?q=test) in the browser?
Also I can't find any documentation (it's hard to google it), but it wouldn't hurt to make the opening tag <?php instead of just <?

Data output using Ajax with PHP

I will break this question into paragraphs for easier reference.
I have a script that calls a php file using Ajax; the script is executed once a button is pressed.
The PHP file contains a simple code that plusses a number with 1.
<?php
$response = $response + 1;
echo $response;
?>
However, something goes wrong when the button is pressed multiple times. I have done some research and I can conclude that there is either something wrong with the simple PHP script that I have made, or the code is only executed once per page reload.
I read an article explaining a lot of work using Javascript if I want an Ajax command to execute multiple times during the same script but I don't see the reason that it can't execute multiple times already when the button is pressed.
Question: Is the PHP file "post.php" even getting executed everytime the button is pressed? Is it something with my PHP file?
How can I make the script plus the number by 1 everytime the button is pressed? And is it because I need some extra Javascript to do that?
The rest of the script is here:
<head>
<script>
function loadXMLDoc()
{
var xmlhttp;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("POST","post.php",true);
xmlhttp.send();
}
</script>
</head>
<body>
<p>This button will execute an Ajax function</p>
<button type="button" onclick="loadXMLDoc()">Press here!</button>
<div id="myDiv"></div>
<script type="text/javascript" src="http://www.parameter.dk/counter/5b0d9873158158e08cad4c71256eb27c"></script>
</body>
If I wasn't clear enough at some point, please pick out the paragraph number and I'll deepen that part.
In your code $response is always 1 because php by default have no state. You can fix it by saving response inside a session.
session_start();
if (isset($_SESSION['response'])) {
$_SESSION['response'] = $_SESSION['response'] + 1;
} else {
$_SESSION['response'] = 1;
}
echo $_SESSION['response'];

Insert MySQL record with PHP and AJAX

trying to insert a record in my DB using AJAX for the very first time. I have the following...
Form
<form>
<input type="text" id="salary" name="salary">
<input type="button" onclick="insertSalary()">
</form>
AJAX
<script type="text/javascript">
function insertSalary()
{
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById('current-salary').innerHTML=xmlhttp.responseText;
}
};
xmlhttp.open("POST","insert_salary.php",true);
xmlhttp.send("salary=" + document.getElementById("salary").value);
}
</script>
PHP
$uid = $_SESSION['oauth_id'];
$monthly_income = mysql_real_escape_string($_POST['salary']);
#Insert a new Record
$query = mysql_query("INSERT INTO `income` (user_id, monthly_income) VALUES ($uid, '$monthly_income')") or die(mysql_error());
$result = mysql_fetch_array($query);
return $result;
Nowmy data is being inserted into the table BESIDES the 'salary' which is being inputted as '0'
Once inserted I also have a div 'current-salary' that should then be populated with there inputted value only it isnt, Can anybody help me to understand where im going wrong?
If you want to save your self a lot of time, effort, and heartache, use the jquery library for your ajax requests. You can download it at http://jquery.com/
After adding a reference(Script tag) to the jquery script your javascript for the ajax request would become:
function insertSalary()
{
var salary = $("#salary").val();
$.post('insert_salary.php', {salary: salary}, function(data)
{
$("#current-salary").html(data);
});
}
Also keep in mind that using "insert_salary.php" as the url means it is a relative path and must be in the folder of the current running script.
Your php script needs to echo whatever you would like to be injected into your current-salary tag also.

How to recognise if user clicked out of text input and run php in that event

How can I use javascript to check, if the user clicks out of my text input class = "foo", and then, if the user has done so, execute a php file.
The easiest way to go about doing this, is to use jQuery.
First, include jQuery in your <head></head> section:
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.0/jquery.min.js"></script>
Then add in the following Javascript:
$(document).ready(function() {
$('input.foo').blur(function(){
$.ajax('myScript.php');
});
});
This will setup the input (who's class is foo) to use ajax to run myScript.php whenever someone clicks out of it, which in development terms is called blurring.
Here an example with plain javascript.
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
function runAjax(){
if (str==""){
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest){ // code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function(){
if (xmlhttp.readyState==4 && xmlhttp.status==200){
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","fooscript.php",true);
xmlhttp.send();
}
</script>
<form>
<input name="vorname" type="text" onblur="runAjax()">
</form>
</body>
</html>
Maybe it's a good idea to use a javascript framework like jQuery. I've stolen this example from here.

Ajax dropdown php table sorting

I have a page which has a dropdown box. On selection a value is sent to a php script (Ajax), based on the value a html table is created and sent back to the responseText. The table is output to the HTML page. I want the table to have sortable columns, so I have used jQuery datatables for this, but it is not working.
I have cut and pasted the exact table into the html and ran the page, and then sorting works.
Please can anyone help / advise to fix this?
Note the table output from the php is outputted inbetween:
<a div id="txtHint"> <table id="example"> <div>
Here is the rest of the code on the HTML page:
<script type="text/javascript" src="/js/jquery-1.5.1.js"></script>
<script type="text/javascript" src="/js/jquery.dataTables.js"></script>
<script type="text/javascript" charset="utf-8">
$(document).ready(function() {
$('table#example').dataTable( {
"sPaginationType": "full_numbers"
} );
} );
</script>
<script type="text/javascript">
function selMetal(str,str2){
if (str==""){
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest){
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}else{
// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function(){
if (xmlhttp.readyState==4 && xmlhttp.status==200){
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","sql.php?m="+str+"&s="+str2,true);
xmlhttp.send();
}
</script>
Where is #example defined? Are you recreating the html for the entire table in ajax?
If so, you are probably overwriting the #example dom element that jquery dataTable already manipulated. Try re-instantiating the data table after you set the table html, such as:
xmlhttp.onreadystatechange=function(){
if (xmlhttp.readyState==4 && xmlhttp.status==200){
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
$('table#example').dataTable().fnDestroy(); // might need to destroy the old one first - not sure
$('table#example').dataTable( { "sPaginationType": "full_numbers" } );
}
}

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