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Using AJAX to get an SQL WHERE query into javascript

I am trying to pass a javascript variable into an SQL WHERE query and I keep getting null in return.
On-click of a button, the buttonClick function is ran:
<script>
var var1;
function buttonClick(elem){
var1 = elem.src //this gets the url from the element
var path = var1.slice(48); //this cuts the url to img/art/9/1.jpg
ajax = theAjax(path);
ajax.done(processData);
ajax.fail(function(){alert("Failure");});
}
function theAjax(path){
return $.ajax({
url: 'info.php',
type: 'POST',
data: {path: path},
});
}
function processData(response_in){
var response = JSON.parse(response_in);
console.log(response);
}
</script>
Here is the code stored in the info.php file:
<?php
$path = $_POST['path'];
$result3 = mysqli_query("SELECT itemName from images WHERE imgPath='$path'");
$json = json_encode($result3);
echo $json
?>
As you can see, once I click the button, the buttonClick() function is ran and a variable stores the image path or src. That path variable is send to theAjax() function where it is passed to the info.php page. In the info.php page, the SQL WHERE query is ran and returned to the processData() function to be parsed and printed in the developer console. The value printed shows null.
Below is a picture of what I am trying to get from the database:

1.Check that path is correct or not? you can check inside jquery using console.log(path); or at PHP end by using print_r($_POST['path']);
2.Your Php code missed connection object as well as record fetching code.
<?php
if(isset($_POST['path'])){
$path = $_POST['path'];
$conn = mysqli_connect ('provide hostname here','provide username here','provide password here','provide dbname here') or die(mysqli_connect_error());
$result3 = mysqli_query($conn,"SELECT itemName from images WHERE imgPath='$path'");
$result = []; //create an array
while($row = mysqli_fetch_assoc($result3)) {
$result[] = $row; //assign records to array
}
$json = json_encode($result); //encode response
echo $json; //send response to ajax
}
?>
Note:- this PHP query code is wide-open for SQL INJECTION. So try to use prepared statements of mysqli_* Or PDO.

mysqli_query() required 1st parameter as connection object.
$result3 = mysqli_query($conn,"SELECT itemName from images WHERE imgPath='$path'"); // pass your connection object here

I think your issue is that you're trying to encode a database resource.
Try adjusting your PHP to look like the following:
<?php
$path = $_POST['path'];
$result3 = mysqli_query("SELECT itemName from images WHERE imgPath='$path'");
$return_data = [];
while($row = mysqli_fetch_assoc($result3)) {
$return_data[] = $row;
}
$json = json_encode($return_data);
echo $json
?>

Getting a value from Javascript in PHP [duplicate]

This question already has answers here:
What is the difference between client-side and server-side programming?
(3 answers)
Closed 7 years ago.
I am not very experienced in web programming and am attempting to run a script which updates my database.
<script>
function myFunction() {
var texts = document.getElementById("content").textContent;
alert(texts)
<?php
include_once 'accounts/config.php';
$text = ...;
$tbl_name='enemies'; // Table name
$query = "UPDATE enemies SET text=('$text') WHERE id=1";
$result = mysql_query($query) or die(mysql_error());
?>
}
</script>
I have no idea what to put in the $text section as shown with $text = ...; in order to get the variable texts from above.
EDIT
I have updated my code but the function does not seem to be accessing the PHP file. I am using a button to call the function and I have also tested it so i know the function is being called. My file is called update.php and is in the same directory as this file.
<button onclick="myFunction()">Click This</button>
<script>
function myFunction() {
var texts = document.getElementById("content").textContent;
$.ajax({
url: "update.php",
type: "POST",
data: {texts:texts},
success: function(response){
}
});
}
</script>

you can post your $texts value to other php page using ajax and get the variable on php page using $_POST['texts'] and place update query there and enjoy....
function myFunction() {
var texts = document.getElementById("content").textContent;
$.ajax({
url: 'update.php',
type: "POST",
data: {texts:texts},
success: function(response)
{
}
});
And your php file will be named as update.php
<?php
include_once 'accounts/config.php';
$text =$_POST['texts'];
$tbl_name='enemies'; // Table name
$query = "UPDATE `enemies` SET `text`='".$text."' WHERE `id`=1";
$result = mysql_query($query) or die(mysql_error());
?>

PHP runs on the server and then generates output which is then returned to the client side. You can't have a JavaScript function make a call to inlined PHP since the PHP runs before the JavaScript is ever delivered to the client side.
Instead, what you'd need to do is have your function make an AJAX request to a server-side PHP script that then extracts the data from the request body and then stores it in the database.
PHP: "/yourPhpScript.php"
<?php
include_once 'accounts/config.php';
$text = $_POST['data'];
$tbl_name='enemies'; // Table name
$query = "UPDATE enemies SET text='".$text.'" WHERE id=1";
$result = mysql_query($query) or die(mysql_error());
?>
JavaScript:
function myFunction() {
var texts = document.getElementById("content").textContent;
alert(texts);
// append data as a query string
var params = 'data='+texts;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
// when server responds, output any response, if applicable
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
// replace with the filename of your PHP script that will do the update.
var url = '/yourPhpScript.php';
xmlhttp.open("POST", url, true);
xmlhttp.send(params);
}
A word of caution: This is not a safe, production-friendly way of updating data in your database. This code is open to SQL injection attacks, which is outside the scope of your question. Please see Bobby Tables: A guide to preventing SQL injection if you are writing code that will go into production.

You are wrong in approach
You should use ajax to post 'texts' value to your php script
https://api.jquery.com/jquery.post/ and create separate php file where you will get data from ajax post and update DB
javascript:
<script>
function myFunction() {
var texts = document.getElementById("content").textContent;
$.ajax({
type: "POST",
url: "update.php",
data: "texsts=" + texts,
success: success
});
}
</script>
update.php
<?php
include_once 'accounts/config.php';
$text = $_POST['texts'];
$tbl_name='enemies'; // Table name
$query = "UPDATE enemies SET text=('$text') WHERE id=1";
$result = mysql_query($query) or die(mysql_error());
?>

i will use PDO if i was you, what you do mysql_query are outdated, if you use my framework https://github.com/parisnakitakejser/PinkCowFramework you can do the following code.
<?php
include('config.php');
$text = $_POST['text'];
$query = PinkCow\Database::prepare("UPDATE enemies SET text = :text WHERE id = 1");
$bindparam = array(
array('text', $text, 'str')
);
PinkCow\Database::exec($query,$bindparam);
$jsonArray = array(
'status' => 200
);
echo json_encode($jsonArray);
?>
place this code in jsonUpdateEnemies.php file and call it width jQuery
<script>
function myFunction(yourText) {
$.post( 'jsonUpdateEnemies.php', {
'text' : yourText
}, function(data)
{
alert('Data updated');
},'json');
}
</script>
its a little more complex then you ask about, but its how i will resolved your problem, :)

Ajax Request not returning PHP Loop Echo

The PHP is working fine when directly called in browser, but the ajax.responseText does not contain anything given out by the While Loop.
$result = $mysqli->query("SELECT * FROM `Dienstplan` WHERE MONTH(Datum) = '$Monat'");
while ($row = $result->fetch_assoc()) {
$Datum = $row['Datum'];
$Datum = strtotime($Datum);
$Datum = date('d.m.Y',$Datum);
$Tag = $row['Tag'];
$Dienst = $row['Dienst'];
//echo '<tr><td>'.$Tag.' '.$Datum.' '.$Dienst.'</td></tr>';
echo $Tag.' '.$Datum.' '.$Dienst.'';
}
echo "This is a Test!";
The ajax.responseText only contains the last echo after the While Loop. But when I call the PHP script directly in my Browser I can clearly see all the data given out by the loop. For some reason it's not contained in the Ajaxresponse.
Here is the Ajax Code:
var ajax;
ajax = new XMLHttpRequest();
ajax.open("GET","../php/FTL_Month_2.php",true);
ajax.send();
ajax.onreadystatechange=function(){
if (ajax.readyState==4 && ajax.status==200){
//alert(ajax.responseText);
document.getElementById("DataList").innerHTML=ajax.responseText;
}
}

As a best practice, you should get all the data you want to return, and store it in a variable. after that, out of the loop, echo this variable.

Why my php array return only recent/last post activities

I create a jquery which sent data to a php file and after query(If any data found at sql) php return data to jquery by json_encode for append it.
Jquery sent two type data to php file:
1st: page id
2nd: post ids (a jquery array sent them to php file)
If I used print_r($_REQUEST['CID']); exit; on php file for test what he get from jquery, Its return and display all post ids well.
But if I make any reply on particular post, Its only return recent post reply.
That means, if I have 3 post like: post-1st, post-2nd, post-3rd ; my php return only post-3rd activities.
I want my script update any post reply when it submitted at sql.
my wall.php
// id is dynamic
<div class="case" data-post-id="111"></div>
<div class="case" data-post-id="222"></div>
<div class="case" data-post-id="333"></div>
//Check for any update after 15 second interval by post id.
<script type="text/javascript" charset="utf-8">
var CID = [];
$('div[data-post-id]').each(function(i){
CID[i] = $(this).data('post-id');
});
function addrep(type, msg){
CID.forEach(function(id){
$("#newreply"+id).append("<div class='"+ type +""+ msg.id +"'><ul>"+ msg.detail +"</ul></div>");
});
}
var tutid = '<?php echo $tutid; ?>';
function waitForRep(){
$.ajax({
type: "GET",
url: "/server.php",
cache: false,
data: {
tutid : tutid,
CID : CID
},
timeout:15000,
success: function(data){
addrep("postreply", data);
setTimeout(
waitForRep,
15000
);
},
error: function(XMLHttpRequest, textStatus, errorThrown){
setTimeout(
waitForRep,
15000);
}
});
}
$(document).ready(function(){
waitForRep();
});
</script>
server.php (may be problem in my array or something else)
while (true) {
if($_REQUEST['tutid'] && $_REQUEST['CID']){
foreach($_REQUEST['CID'] as $key => $value){
date_default_timezone_set('Asia/Dhaka');
$datetime = date('Y-m-d H:i:s', strtotime('-15 second'));
$res = mysqli_query($dbh,"SELECT * FROM comments_reply WHERE post_id =".$value." AND qazi_id=".$_REQUEST['tutid']." AND date >= '$datetime' ORDER BY id DESC LIMIT 1") or die(mysqli_error($dbh));
} // array close
$rows = mysqli_fetch_assoc($res);
$row[] = array_map('utf8_encode', $rows);
$data = array();
$data['id'] = $rows['id'];
$data['qazi_id'] = $rows['qazi_id'];
//ect all
// do something and echo $data['detail'] = $detail;
if (!empty($data)) {
echo json_encode($data);
flush();
exit(0);
}
} // request close
sleep(5);
} // while close

Try to declare CID array like this:
var CID = new Array();

It looks like you're looping through the CIDs and running an SQL query for each one, but you're only retrieving the results once, outside of the loop. You'll only get the last query's results if you run
$rows = mysqli_fetch_assoc($res);
outside of the CIDs foreach loop.
#koc:
Unfortunately, it won't be as simple as moving the closing loop bracket. If you're trying to retrieve multiple datasets in one AJAX call, then you'll need to handle multiple datasets in your AJAX's success callback, or in your addrep() function. Here's one way to do it, but you can do it many different ways depending on what you're ultimately trying to do:
while (true) {
if($_REQUEST['tutid'] && $_REQUEST['CID']){
$data = array();
foreach($_REQUEST['CID'] as $key => $value){
date_default_timezone_set('Asia/Dhaka');
$datetime = date('Y-m-d H:i:s', strtotime('-15 second'));
$res = mysqli_query($dbh,"
SELECT *
FROM comments_reply
WHERE post_id =".$value."
AND qazi_id=".$_REQUEST['tutid']."
AND date >= '$datetime'
ORDER BY id DESC LIMIT 1
") or die(mysqli_error($dbh));
$row = mysqli_fetch_assoc($res)
$data[] = array_map('utf8_encode', $row);
} // array close
//$rows = mysqli_fetch_assoc($res);
//$row[] = array_map('utf8_encode', $rows);
//$data = array();
//$data['id'] = $rows['id'];
//$data['qazi_id'] = $rows['qazi_id'];
//ect all
// do something and echo $data['detail'] = $detail;
if (!empty($data)) {
echo json_encode($data);
flush();
exit(0);
}
} // request close
sleep(5);
} // while close
then in your Javascript:
...
success: function(data){
for (var i=0, len=data.length; i<len; i++) {
addrep("postreply", data[i]);
}
setTimeout(waitForRep, 15000);
},
...
But again, that's just an example. I don't really know what your datasets look like or how you want the data to be passed around and used. This is just an idea that hopefully gets you going in the right direction.

Trouble with php variables and ajax javascript

ok I have edited this to another couple of questions I've asked on a similar issue, but I really am in a rush so thought I'd start a new one, sorry if it bothers anyone.
first I have a php script on test.php on the apache server
<?php
//create connection
$con = mysqli_connect("localhost", "user", "password", "dbname");
//check connection
if (mysqli_connect_errno()){
echo "failed to connect to MySQL: " . mysqli_connect_error();
}
$grab = mysqli_query($con, "SELECT * FROM table");
$row = mysqli_fetch_array($grab);
$name = $row["name"];
$color = $row["color"];
$price = $row["price"];
$n1 = $name[0];
$c1 = $color[0];
$p1 = $price[0];
?>
Then I've got this ajax script set to fire onload of page a webpage written in html. so the load() function is onload of the page in the body tag. This script is in the head.
function load(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET", "test.php", true);
xmlhttp.send();
xmlhttp.onreadystatecahnge = function(){
if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
document.getElementById("itemNameLink1").innerHTML = "<?php echo $n1;?>;
}
}
}
ok so what I want is the $n1 variable in the php script to be used in the javascript ajax code. Where the script is, but I'm not sure where or how to make use of the variable, I've tried a few things. All that happens right now is the innerHTML of itemNameLink1 just disappears.
I'm quite new so any advise would be appreciated, thanks.

The response (this is what you echo in php) returned from request you can get by responseText attribute of XMLHttpRequest object.
So first your JS code should be:
function load(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET", "test.php", true);
xmlhttp.send();
xmlhttp.onreadystatecahnge = function(){
if(xmlhttp.readyState == 4 && xmlhttp.status == 200){
document.getElementById("itemNameLink1").innerHTML = xmlhttp.responseText;
}
}
}
now in php echo $n1 variable:
....
$grab = mysqli_query($con, "SELECT * FROM table");
$row = mysqli_fetch_array($grab);
$name = $row["name"];
$color = $row["color"];
$price = $row["price"];
$n1 = $name[0];
$c1 = $color[0];
$p1 = $price[0];
// echo it to be returned to the request
echo $n1;
Update to use JSON for multiple variables
so if we do this:
$name = $row["name"];
$color = $row["color"];
$price = $row["price"];
$response = array
(
'name' => $name,
'color' => $color,
'price' => $price
);
echo json_encode($response);
Then in javascript we can parse it again to have data object containing 3 variables.
var data = JSON.parse(xmlhttp.responseText);
//for debugging you can log it to console to see the result
console.log(data);
document.getElementById("itemNameLink1").innerHTML = data.name; // or xmlhttp.responseText to see the response as text
Fetching all the rows:
$row = mysqli_fetch_array($grab); // this will fetch the data only once
you need to cycle through the result-set got from database: also better for performance to use assoc instead of array
$names = $color = $price = array();
while($row = mysqli_fetch_assoc($grab))
{
$names[] = $row['name'];
$color[] = $row['color'];
$price[] = $row['price'];
}
$response = array
(
'names' => $names,
'color' => $color,
'price' => $price
);

You can dynamically generate a javascript document with php that contains server side variables declared as javascript variables, and then link this in the head of your document, and then include this into your document head whenever server side variables are needed. This will also allow you to dynamically update the variable values upon page generation, so for example if you had a nonce or something that needs to change on each page load, the correct value can be passed upon each page load. to do this, you need to do a few things. First, create a php script and declare the correct headers for it to be interpreted as a script:
jsVars.php:
<?php
//declare javascript doc type
header("Content-type: text/javascript; charset=utf-8");
//tell the request not to cache this file so updated variables will not be incorrect if they change
header('Cache-Control: no-cache, no-store, must-revalidate'); // HTTP 1.1.
header('Pragma: no-cache'); // HTTP 1.0.
header('Expires: 0'); // Proxies.
//create the javascript object
?>
var account = {
email: <?= $n1; ?>,
//if you need other account information, you can also add those into the object here
username: <?= /*some username variable here for example */ ?>
}
You can repeat this for any other information you need to pass to javascript on page load, and then reference your data using the namespaced javascript object (using object namespacing will prevent collisions with other script variables that may not have been anticipated.) wherever it is needed as follows:
<script type="text/javascript>
//put this wherever you need to reference the email in your javascript, or reference it directly with account.email
var email = account.email;
</script>
You can also put a conditional statement into the head of your document so it will only load on pages where it is needed (or if any permission checks or other criteria pass as well). If you load this before your other scripting files, it will be available in all of them, provided you are using it in a higher scope than your request.
<head>
<?php
//set the $require_user_info to true before page render when you require this info in your javascript so it only loads on pages where it is needed.
if($require_user_info == TRUE): ?>
<script type="text/javascript" href="http://example.com/path-to-your-script/jsVars.php" />
<?php endif; ?>
<script type="text/javascript" href="your-other-script-files-that-normally-load" />
</head>
You can also do this for any other scripts that have to load under specific criteria from the server.

You should define the PHP variable. And use that variable in your javascript:
<?php
$n1 = "asd";
?>
<html>
<head></head>
<body>
<div id="itemNameLink1"></div>
<script>
function load()
{
var xmlhttp = new XMLHttpRequest();
xmlhttp.open('GET', '/test.php', true);
xmlhttp.send(null);
//Note you used `onreadystatecahnge` instead of `onreadystatechange`
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("itemNameLink1").innerHTML = '<?=$n1?>';
}
}
}
load();
</script>
</body>
</html>