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Get data from database using php,ajax

I have a simple section in which I am displaying data from the database, my database looks like this.
Now I have four buttons looks like this
When a user clicks one of the above buttons it displays this
So now when user eg select construction and next select eg Egypt' in the console and clicks buttonconfirmdisplays [855,599075], user can select multiple countries, this works as expected forconstruction ,power,oil`,
Now I want if user eg clicks All available industries button in those four buttons and next select eg Egypt and click confirm it should display
the sum of egypt total projects in construction, oil, power sector 855+337+406 =1598 and the sum of total budgets in both sectors 1136173
Here is my solution
HTML
<div id="interactive-layers">
<div buttonid="43" class="video-btns">
<span class="label">Construction</span></div>
<div buttonid="44" class="video-btns">
<span class="label">Power</span></div>
<div buttonid="45" class="video-btns">
<span class="label">Oil</span></div>
<div buttonid="103" class="video-btns">
<span class="label">All available industries</span>
</div>
</div>
Here is js ajax
$("#interactive-layers").on("click", ".video-btns", function(){
if( $(e.target).find("span.label").html()=="Confirm" ) {
var selectedCountries = [];
$('.video-btns .selected').each(function () {
selectedCountries.push( $(this).parent().find("span.label").html() ) ;
});
if( selectedCountries.length>0 ) {
if(selectedCountries.indexOf("All available countries")>-1) {
selectedCountries = [];
}
} else {
return;
}
var ajaxurl = "";
if(selectedCountries.length>0) {
ajaxurl = "data.php";
} else {
ajaxurl = "dataall.php";
}
$.ajax({
url: ajaxurl,
type: 'POST',
data: {
countries: selectedCountries.join(","),
sector: selectedSector
},
success: function(result){
console.log(result);
result = JSON.parse(result);
$(".video-btns").each(function () {
var getBtn = $(this).attr('buttonid');
if (getBtn == 106) {
var totalProjects = $("<span class='totalprojects'>"+ result[0] + "</span>");
$(this).append(totalProjects)
}else if(getBtn ==107){
var resultBudget = result[1]
var totalBudgets = $("<span class='totalbudget'>"+ '&#36m' +" " + resultBudget +"</span>");
$(this).append( totalBudgets)
}
});
return;
}
});
}
});
Here is php to get all dataall.php
$selectedSectorByUser = $_POST['sector'];
$conn = mysqli_connect("localhost", "root", "", "love");
$result = mysqli_query($conn, "SELECT * FROM meed");
$data = array();
$wynik = [];
$totalProjects = 0;
$totalBudget = 0;
while ($row = mysqli_fetch_array($result))
{
if($row['Sector']==$selectedSectorByUser ) {
$totalProjects+= $row['SumofNoOfProjects'];
$totalBudget+= $row['SumofTotalBudgetValue'];
}
}
echo json_encode([ $totalProjects, $totalBudget ] );
exit();
?>
Here is data.php
<?php
$selectedSectorByUser = $_POST['sector'];
$countries = explode(",", $_POST['countries']);
//var_dump($countries);
$conn = mysqli_connect("localhost", "root", "", "meedadb");
$result = mysqli_query($conn, "SELECT * FROM meed");
$data = array();
$wynik = [];
$totalProjects = 0;
$totalBudget = 0;
while ($row = mysqli_fetch_array($result))
{
if($row['Sector']==$selectedSectorByUser && in_array($row['Countries'],$countries ) ) {
// array_push($data, $row);
$totalProjects+= $row['SumofNoOfProjects'];
$totalBudget+= $row['SumofTotalBudgetValue'];
}
}
// array_push($wynik, $row);
echo json_encode([ $totalProjects, $totalBudget ] );
//echo json_encode($data);
exit();
?>
Now when the user clicks All available industries btn and selects a country I get [0,0] on the console.
What do I need to change to get what I want? any help or suggestion will be appreciated,

in you dataAll.php
If you have select All available industries
you shold not check for sector because you need all sector (eventually you should check for countries )
so you should avoid the check for this condition
<?php
$conn = mysqli_connect("localhost", "root", "", "love");
$result = mysqli_query($conn, "SELECT * FROM meed");
$data = [];
$wynik = [];
$totalProjects = 0;
$totalBudget = 0;
while ($row = mysqli_fetch_array($result)) {
$totalProjects += $row['SumofNoOfProjects'];
$totalBudget += $row['SumofTotalBudgetValue'];
}
echo json_encode([$totalProjects, $totalBudget]);

You can use the SQL JOIN operator, or in this case an implicit join would be cleanest:
$result = mysqli_query($conn, "SELECT * FROM construction, power, oil_and_gas, industrial WHERE construction.Countries = power.Countries AND power.Countries = oil_and_gas.Countries AND oil_and_gas.Countries = industrial.Countries");
You need the WHERE conditions so it knows how the rows of each different table are related to each other. You can shorten it a bit with aliases for the tables:
$result = mysqli_query($conn, "SELECT * FROM construction as C, power as P, oil_and_gas as G, industrial as I WHERE C.Countries = P.Countries AND P.Countries = G.Countries AND G.Countries = I.Countries");
In this case, however, I think you may want to consider changing the structure of your database. It seems like you repeat columns quite a bit across them. Perhaps these can all be in a single table, with a "type" column that specifies whether it's power, construction, etc. Then you can query just the one table and group by country name to get all your results without the messy joins across 4 tables.

The single table looks OK.
(The rest of this Answer is not complete, but might be useful.)
First, let's design the URL that will request the data.
.../foo.php?industry=...&country=...
But, rather than special casing the "all" in the client, do it in the server. That is, the last button for industry will generate
?industry=all
and the PHP code will not include this in the WHERE clause:
AND industry IN (...)
Similarly for &country=all versus &country=egypt,iran,iraq
Now, let me focus briefly on the PHP:
$wheres = array();
$industry = #$_GET['industry'];
if (! isset($industry)) { ...issue error message or use some default... }
elseif ($industry != 'all') {
$inds = array();
foreach (explode(',', $industry) as $ind) {
// .. should test validity here; left to user ...
$inds[] = "'$ind'";
}
$wheres[] = "industry IN (" . implode(',', $inds) . )";
}
// ... repeat for country ...
$where_clause = '';
if (! empty($wheres)) {
$where_clause = "WHERE " . implode(' AND ', $wheres);
}
// (Note that this is a generic way to build arbitrary WHEREs from the data)
// Build the SQL:
$sql = "SELECT ... FROM ...
$where_clause
ORDER BY ...";
// then execute it via mysqli or pdo (NOT mysql_query)
Now, let's talk about using AJAX. Or not. There were 2 choices:
you could have had the call to PHP be via a GET and have that PHP display a new page. This means that PHP will be constructing the table of results.
you could have used AJAX to request the data. This means that Javascript will be constructing the data of results.
Which choice to pick probably depends on which language you are more comfortable in.

How to use javascript if statements within function to populate table

I've created a search page that sends results to a table with the ability to click on a specific record which then opens another page in the desired format.
I'd like to do is be able to open different formatted pages based on the data returned in the search query but I'm having a bit of trouble pulling it all together.
Here's the PHP used to request and retrieve the data from the database, as well as populate it in a table where each record can be selected and used to populate a planner page with all the proper formatting:
$search = $_POST['search'].'%';
$ment = $_POST['ment'];
$stmt = $link->prepare("SELECT lname, fname, rank, reserve, ment1, pkey FROM planner WHERE lname LIKE ? AND ment1 LIKE ? ORDER BY lname, fname");
$stmt->bind_param('ss', $search, $ment);
$stmt->execute();
$result = $stmt->get_result();
if ($result->num_rows > 0) {
echo "<table><tr><th>Last Name</th><th>First Name</th><th>Rank</th><th>Mentor Group</th><th></th></tr>";
while($row = $result->fetch_assoc()) {
$rsv = $row['reserve'];
$pkey = $row['pkey'];
echo "<tr><td>".$row['lname']."</td><td>".$row['fname']."</td><td>".$row['rank']."</td><td>".$row['ment1']."</td><td><button onClick=getPlanner('".$pkey."');>Get Planner</button></td></tr>";
}
echo "</table>";
} else {
echo "0 results";
}
Now the fun part. I want to open different pages based on the information contained in the record. I've got it working for the pkey variable by itself with a single javascript function. However, if I want to open a differently formatted page using the same function using if, else statements, the table only populates with the link page based on the last record compared. Here is my attempt to get the JavaScript with the if, else statements working but it only uses the format of the last record that's compared.
var pkey = <?php echo json_encode($pkey); ?>;
var rsv = <?php echo $rsv ?>;
//var check = document.write(rsv);
function getPlanner(pkey) {
if(rsv != 0){
var plan = window.open("../php/plannerR.php?pln=" + pkey);
} else {
var plan = window.open("../php/planner.php?pln=" + pkey);
}
}
How do I get the 'Get Planner' button to open the correctly formatted planner page based on the users specific information?

To make things easier I'd suggest the following:
Do the logic already in php when generating the html-table (and the link).
while($row = $result->fetch_assoc()) {
$rsv = $row['reserve'];
$pkey = $row['pkey'];
if($rsv) { // thats basicly the same as !=0
$target='../php/plannerR.php'
} else {
$target='../php/planner.php'
}
echo "<tr><td>".$row['lname']."</td><td>".$row['fname']."</td>";
echo "<td>".$row['rank']."</td><td>".$row['ment1']."</td>";
echo "<td><a class='button styleIt' href='".$target."?pkey=".$pkey."&rsv=".$rsv."'>Get Planner</a></td></tr>";
}
If you wanna stick to your js solution (which is more hassle unless you really need it) you can of course go with the solution from my comments that you already successfully implemented (and posted as answer so others can see the implementetion).

Thanks to Jeff I played around a bit with bringing both variables into the function and got it to work. Final code below.
$search = $_POST['search'].'%';
$ment = $_POST['ment'];
$stmt = $link->prepare("SELECT lname, fname, rank, reserve, ment1, pkey FROM planner WHERE lname LIKE ? AND ment1 LIKE ? ORDER BY lname, fname");
$stmt->bind_param('ss', $search, $ment);
$stmt->execute();
$result = $stmt->get_result();
if ($result->num_rows > 0) {
echo "<table><tr><th>Last Name</th><th>First Name</th><th>Rank</th><th>Mentor Group</th><th></th></tr>";
while($row = $result->fetch_assoc()) {
$rsv = $row['reserve'];
$pkey = $row['pkey'];
echo "<tr><td>".$row['lname']."</td><td>".$row['fname']."</td><td>".$row['rank']."</td><td>".$row['ment1']."</td><td><button onClick=getPlanner('".$pkey."','".$rsv."');>Get Planner</button></td></tr>";
}
echo "</table>";
} else {
echo "0 results";
}
var pkey = <?php echo json_encode($pkey); ?>;
var rsv = <?php echo $rsv ?>;
//var check = document.write(rsv);
function getPlanner(pkey, rsv) {
if(rsv != 0){
var plan = window.open("../php/plannerR.php?pln=" + pkey);
}
else{
var plan = window.open("../php/planner.php?pln=" + pkey);
}
}

How to limit voting function in a Facebook App once per day?

I'm really new at back-end stuff and I'm building a Facebook app with multiple photo entries with voting mechanics. You can vote one or multiple entries once per day and it also detects your Facebook ID so that when you vote, the database detects your Facebook ID, the entry number you voted, and the date you voted. When you vote during the current date, a pop-up will appear that says "you successfully voted". Then when you try again the same date, the pop-up's message will change and instead, it will say "try to vote again tomorrow". It also shows the number of votes on the entry page.
My only problem is that when you're a first time user, it works fine, you can vote all the entries on the current date, but then when you come back the next day, when you vote, the pop-up will still say that you already voted, and the vote count will not update.
Here's the code for the PHP page: (edited this, already solved the problem, thanks for the help)
date_default_timezone_set('Asia/Manila');
// Get last vote date: fetch_date_voted returns none if user voted for first time
$current_date = date('Y-m-d');
$fetch_date_return = $this->fetch_date_voted($entry_id, $facebook_id, $table_prefix, $conn);
$last_vote_date = $fetch_date_return['last_date'];
$return['date_last_voted'] = $fetch_date_return;
// Below is a code i got from stackoverflow - 844641242329946 (kristina id)
/*if( $last_vote_date && ($last_vote_date == "none" || (strtotime($last_vote_date) + (60*60*24)) < strtotime($current_date))){*/
// Below is the original code
if( $last_vote_date == "none" || $last_vote_date < $current_date ) {
$table_name = $table_prefix . '_voter';
$query = $conn->query("
INSERT INTO $table_name
(facebook_id, entry_id, date_voted)
VALUES
($facebook_id, $entry_id, '$current_date')
");
//
// After doing INSERT, the variable $query will return a TRUE status
if ( $query ) {
// If the date fetched is TRUE, it will UPDATE
$update = $this->update_count($entry_id, $table_prefix, $conn);
// If update is successful, it will fetch the latest vote_count
if($update) {
$fetched_data = $this->fetch_current_count($entry_id, $table_prefix, $conn);
if ($fetched_data['status']) {
$return['status'] = true;
$return['vote_count'] = $fetched_data['vote_count'];
} else {
$return['status'] = false;
}
} else {
$return['status'] = false;
}
} else {
die('Error : ('. $conn->errno .') '. $conn->error);
$return['status'] = false;
$return['error_response'] = $conn->error;
}
} else {
$return['status'] = false;
$return['error_response'] = 'date_invalid';
}
echo json_encode($return);
//$query->close();
$conn->close();
}

$last_vote_date AND $current_date are string representations of a date, convert them to time and it works:
strotime($last_vote_date) < strotime($current_date)
Beware that this will always return true, because you want them to not use it for a day, so it would be:
if( $last_vote_date && ($last_vote_date == "none" || (strtotime($last_vote_date) + (60*60*24)) < strtotime($current_date))){
to add 24 hours.

How to prevent people from spamming an ajax form [closed]

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My problem is I have a vote system similar to the one of Stack Overflow. My problem is that a person can spam the vote up button which makes it glitch and make it submit more times than it’s supposed to. For example, if there are 10 up votes on a post, I could repeatedly click the vote up button and the it would add two or three up votes instead of one. Similarly I could do this with the down vote button. How do I prevent this?
Index.php:
<?php
session_start();
require('db.php');
$pid = 2;
$uid = $_SESSION['id'];
$sql = mysqli_query($con, "SELECT * FROM posts WHERE pid = '$pid'"); //check to see how many likes the post has
$r = mysqli_fetch_assoc($sql);
$body = $r['body'];
$likes = $r['likes'];
$sql2 = mysqli_query($con, "SELECT * FROM likes WHERE pid = '$pid' AND uid = '$uid'"); //check to see if user has voted
$n = mysqli_num_rows($sql2);
if ($n == 0) {
//user hasn't liked or down vote anything yet
$liked = "no";
} else {
if ($n > 1) {
//like scammed
echo "<script>alert('Stop spamming for votes. You are banned for spam.')</script>";
exit("You have been banned for spam");
//This isn't fool proof though, and I don't want to ban people for this. It would be best if I could just prevent the vote scam in the first place
}
$r = mysqli_fetch_assoc($sql2);
$type = $r['like_type'];
if ($type == '0') {
$liked = "liked";
} else {
$liked = "disliked";
}
}
?>
<!DOCTYPE html>
<html>
<head>
<title>Test</title>
<script src="//code.jquery.com/jquery-latest.min.js"></script>
<style>
.selected {
color: red;
}
</style>
</head>
<body>
<div class="post">
<p><?php echo $body; ?></p>
</div>
<div class="likes">
Upvote
<span id="votes-<?php echo $pid; ?>"><?php echo $likes; ?></span>
Downvote
</div>
</body>
Javascript vote() function
function vote(type, pid, uid, id, voteId) {
var vote = $('#'+ id);
if (vote.hasClass('selected')) {
//user voted for this
$.post("vote.php", {pid: pid, uid: uid, type: type, vote: 'reset'}, function(d) {
if (d == '0' || d == '1') {
vote.removeClass('selected');
var votes = $('#' + voteId);
var num = votes.text();
if (d == '1') {
votes.text(++num);
} else {
votes.text(--num);
}
} else {
alert('An error occurred')
}
});
} else {
var upVoteId = $('#up-' + pid);
var downVoteId = $('#down-' + pid);
if (upVoteId.hasClass('selected') || downVoteId.hasClass('selected')) {
//user wants to switch votes
$.post('vote.php', {pid: pid, uid: uid, type: type, vote: 'switch'}, function(data) {
var votes = $('#' + voteId);
var num = votes.text();
if (data == '1') {
//downvote successful
votes.text(parseInt(num) - 2);
vote.addClass('selected');
upVoteId.removeClass('selected');
}
if (data == '0') {
//upvote successful
votes.text(parseInt(num) + 2);
vote.addClass('selected');
downVoteId.removeClass('selected');
}
if (d == 'error') {
alert('error');
}
});
} else {
$.post('test2.php', {type: type, pid: pid, uid: uid}, function(d) {
if (d == "1") {
//everything good
$('#' + type + '-<?php echo $pid; ?>').addClass('selected');
var votes = $("#" + voteId).text();
if (type == 'down') {
//downvote
votes = --votes;
$('#' + voteId).text(votes);
} else {
votes = ++votes;
$('#' + voteId).text(votes);
}
} else {
alert('failed');
}
});
}
}
}
}
Vote.php
<?php
session_start();
require('db.php');
if (!isset($_SESSION['id'], $_SESSION['un'])) {
//not logged in
header('Location: index.php');
exit;
} else {
if (!isset($_POST['uid'], $_POST['pid'], $_POST['type'], $_POST['vote'])) {
//form not submitted
header('Location: home.php');
exit;
} else {
$uid = (int)$_SESSION['id'];
$pid = (int)$_POST['pid'];
$type = preg_replace('#[^a-z]#', '', $_POST['type']);
$vote = preg_replace('#[^a-z]#', '',$_POST['vote']); //vote type
if ($vote == 'reset') {
//initiate vote reset
if ($type == 'down') {
//downvote
$sql = mysqli_query($con, "DELETE FROM likes WHERE like_type = '1' AND pid = '$pid' AND uid = '$uid'"); //delete the downvote
$sql2 = mysqli_query($con, "UPDATE posts SET likes = likes + 1 WHERE pid = '$pid'");
if ($sql) {
echo "1"; // 1
exit;
} else {
echo "error";
exit;
}
} else {
//upvote
$sql = mysqli_query($con, "DELETE FROM likes WHERE like_type = '0' AND pid = '$pid' AND uid = '$uid'"); //delete upvote
$sql2 = mysqli_query($con, "UPDATE posts SET likes = likes - 1 WHERE pid = '$pid'");
if ($sql) {
echo "0"; // 0
exit;
} else {
echo "error";
exit;
}
}
}
if ($vote == 'switch') {
//user wanted to switch vote
if ($type == 'down') {
//user had voted up but wants to vote down now
$sql = mysqli_query($con, "DELETE FROM likes WHERE like_type = '0' AND pid = '$pid' AND uid = '$uid'"); //delete the previous vote
$sql2 = mysqli_query($con, "INSERT INTO likes (pid, uid, like_type, date_liked) VALUES ('$pid', '$uid', '1', now())"); //insert new vote
$sql3 = mysqli_query($con, "UPDATE posts SET likes = likes - 2 WHERE pid = '$pid'");
if ($sql AND $sql2 AND $sql3) {
//all three queries were successful
echo "1";
exit;
} else {
echo "error";
exit;
}
} else {
//user had voted down but wants to vote up now
$sql = mysqli_query($con, "DELETE FROM likes WHERE like_type = '1' AND pid = '$pid' AND uid = '$uid'") or die(mysqli_error($con)); //delete the previous vote
$sql2 = mysqli_query($con, "INSERT INTO likes (pid, uid, like_type, date_liked) VALUES ('$pid', '$uid', '0', now())"); //insert new vote
$sql3 = mysqli_query($con, "UPDATE posts SET likes = likes + 2 WHERE pid = '$pid'");
if ($sql AND $sql2 AND $sql3) {
//all three queries were successful
echo "0";
exit;
} else {
echo "error";
exit;
}
}
}
}
}
Test2.php
<?php
require('db.php');
$pid = $_POST['pid'];
$uid = $_POST['uid'];
$type = $_POST['type'];
if ($type == "down") {
//downvote
$type = 1;
$sql = mysqli_query($con, "INSERT INTO likes (uid, pid, like_type, date_liked) VALUES ('$uid', '$pid', '$type', now())");
$sql2 = mysqli_query($con, "UPDATE posts SET likes = likes - 1 WHERE pid = '$pid'");
if ($sql) {
echo '1';
exit;
}
} else {
//upvote
$type = 0;
$sql = mysqli_query($con, "INSERT INTO likes (uid, pid, like_type, date_liked) VALUES ('$uid', '$pid', '$type', now())");
$sql2 = mysqli_query($con, "UPDATE posts SET likes = likes + 1 WHERE pid = '$pid'");
if ($sql) {
echo '1';
exit;
}
}
These are my pages that are currently used. I plan on moving test2.php to vote.php.
In my database I have two tables, one to store all the post details including the number of votes. The second table is to store who voted for what post and if it was an upvote or down.
If I could make my system more efficient, please give me tips or recommendations.

Quick SQL hack: make a unique index on pid,uid so that a user can only ever vote once on a post.
ex: ALTER TABLE vote ADD UNIQUE INDEX pid_uid (pid, uid);
Quick JS hack: set a variable on submit that you don't clear until the response; if the variable is set, you don't submit the form. Thus, spam clicking will do nothing, since every click after the first will be ignored.
ex:
var submitting = false;
function submit_form()
{
if (!submitting)
{
submitting = true;
// example; insert actual arguments for it to work
$.post(
url,
postData,
function (data, textStatus)
{
submitting = false;
// handle data here
},
"json"
);
}
}

Well, there is a lot of improvement to be done.
First you are running open to SQL injection queries. Move that to prepared statement.
Then you can, before insert, check if user already voted for that type, as you already have uid, pid, and like_type. This is server-side.
Client-side your JavaScript could disable clicked button to prevent double click. This will prevent user's to send many requests to the server.
The goal here is let server, PHP, handle the verification if the user already voted to that post, as client -ide is easily manipulated in this case.
Don't forget, move those SQL queries to something safe.

Ultimately, you can only hope to control multiple voting using server-side validation.
Stack Overflow requires the user to sign in to a known account in order to vote, which makes it more difficult (but of course not impossible) for multiple votes.
If you do not require that, the best solution depends on your specific requirements.
A simple, client-only solution is to set a cookie indicating the user has voted. Disable the appropriate UI element if that cookie is set. Someone who clears cookies or uses InPrivate style browsing will easily bypass that. Someone can also write their own client that ignores the cookie. Perhaps it is sufficient for your requirements.
A naive server-side solution is to allow only one vote per IP address. I do not recommend this, but include it so you understand why. Unfortunately, a single user can have multiple IP addresses (just drive down the road on your mobile device and see how many IPs you get), or a single IP can represent multiple physical computers (proxy server).
A solid server-side solution would combine the IP address, user agent, and various aspects of the device to yield a device fingerprint. This is a complex solution, beyond the needs of most websites (but if you need it, there are a few companies out there that offer device fingerprinting). Check out https://panopticlick.eff.org/
Summary
If you can require the user to log in to vote (like StackOverflow), that will often be the best solution.
If you cannot require that, use device fingerprinting if it is in your budget, otherwise rely on a cookie. If you do the latter, it may still be worth logging the IP address and user agent of voters so that you can keep an eye out for blatant cheating.

I'd consider storing a voter's IP address in a mysql table as an INT once they have voted.
After that either just show them the tally, or provide them the option to undo their vote by voting up/down.
Check out the PHP function ip2long:
http://www.php.net/manual/en/function.ip2long.php
Use that to convert the IP address into INT format and store it in your mysql to reference against.
Other Resources:
http://www.php.net/manual/en/function.long2ip.php
http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_inet-aton

Check if user exists with AJAX and PHP

I am trying to create a signup form that checks if the user exists in the database, I inserted a sample user and when I tried signing up with that user it didn't say its already been taken. What have I done wrong?
The JavaScript:
function formSubmit()
{
document.getElementById('email_valid').innerHTML = '';
var temail=document.forms["signup_form"]["temail"].value.replace(/^\s+|\s+$/g, '');
var atpos=temail.indexOf("#");
var dotpos=temail.lastIndexOf(".");
if (atpos<1 || dotpos<atpos+2 || dotpos+2>=temail.length)
{
//alert("Not a valid e-mail address");
setTimeout(function(){document.getElementById('email_valid').innerHTML = '<br/>Email must be valid...';},1000);
var temailsub=0;
}
else
{
$.post('/resources/forms/signup/email.php',{email: temail}, function(data){
document.getElementById('email_valid').innetHTML = data;
if(data.exists){
document.getElementById('email_valid').innetHTML = '<br/>The email address you entered is already in use.';
var temailsub=0;
}else{
var temailsub=1;
}
}, 'JSON');
}
if(temailsub==1e)
{
setTimeout(function(){document.getElementById("signup_form").submit();},1000);
}
else
{
return false;
}
}
The PHP file (email.php):
<?php
header('content-type: text/json');
require_once $_SERVER['DOCUMENT_ROOT']."/resources/settings.php";
$query = $pdo->prepare("SELECT * FROM users WHERE email=:email");
$query->execute(array(
":email"=> $_POST['email']
));
echo json_encode(array('exists' => $query->rowCount() > 0));
?>
I have checked and double checked the code, I still cannot see why its not detecting that the email has already been used... what do i need to do to fix this and avoid this in the future?

The problem is that PDOStatement::rowCount() returns the number of rows affected by the last SQL statement. You are performing a SELECT so this value will always be 0. SELECT does not affect any rows. Instead you need to count the number of rows:
$query = $pdo->prepare("SELECT COUNT(*) FROM users WHERE email=:email");
$query->execute(array(
":email"=> $_POST['email']
));
$rows = $query->fetchColumn();
echo json_encode(array('exists' => $rows);
Also from jtheman's comment above, you should replace innetHTML with innerHTML in your JavaScript.