Ajax and PHP with database connection - php

Question

i have problems with the code below, I'm trying to bring a message of error if the email already exists, but I'm not having success .. Look at the code:
Ajax an jQuery:
<script type="text/javascript">
// Centering the text content
jQuery(window).resize(function () {
boxHeight();
}).load(function() {
boxHeight();
// Show the content and focus the email input
$("#content").fadeIn();
$("#email").focus();
});
jQuery(document).ready(function($){
$('#subscribe').submit(function(e){
e.preventDefault();
email = $('input#email');
email_regex = /^[a-zA-Z0-9._-]+#[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
if(!email_regex.test(email.val())) {
$('#response', form).fadeIn(500, function() {
$('#response', form).html('<p class="message warning" align="center">Invalid email</p>');
});
return;
} else {
$('#response', form).html('<p class="message">Please Wait...</p>');
}
var form = $(this);
var post_url = form.attr('action');
var post_data = form.serialize();
$.ajax({
type: 'POST',
url: post_url,
data: post_data,
success: function(responseText) { if(responseText == 1) {
$('#response', form).html('<p class="message">Error...</p>');
} else { if(responseText == "") {
$(form).fadeOut(500, function(){
form.html(msg).fadeIn();
});
}
}
}
});
});
});
</script>
PHP Database connect:
<?php
$host="xxxx"; // Host name
$username="xxxx"; // Mysql username
$password="xxxx"; // Mysql password
$db_name="xxxx"; // Database name
$tbl_name="xxxx"; // Table name
// Connect to server and select database.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");
// Get values from form
$email = $_POST['email'];
$query = mysql_query("SELECT email FROM banco_emails WHERE 'email' = '$email'");
if(mysql_num_rows($query) == 1) { // if return 1, email exist.
echo '1';
} else {
// Insert data into mysql
$sql="INSERT INTO $tbl_name(email) VALUES ('". $email . "')";
$result=mysql_query($sql);
echo '<p class="message">Thanks for registering. Our bar is getting crowded!</p>';
The problem is that the ajax code does not show the error message, only the message "Please wait ..." and nothing happens, i don't know why...
Sorry for my bad english.
Thanks in advanced!
Problem solved, the problem was in the php code, I did it and it worked!
$query = mysql_query("SELECT email FROM banco_emails WHERE email = '$email' LIMIT 1");
$email_check = mysql_num_rows($query);
if ($email_check > 0) {
echo '1';
} else if ($email_check == 0) {
// Insert data into mysql
$sql="INSERT INTO $tbl_name(email) VALUES ('". $email . "')";
$result=mysql_query($sql);
echo '<p class="message">Thanks for registering. Our bar is getting crowded!</p>';

Answer 1

In your success function you incorrectly handle what PHP returns on success. If the email was new and was added to the database, PHP will echo:
<p class="message">Thanks for registering. Our bar is getting crowded!</p>
Your JS parses the response like this:
if(responseText == 1) {
$('#response', form).html('<p class="message">Error...</p>');
} else {
if(responseText == "") {
$(form).fadeOut(500, function(){
form.html(msg).fadeIn();
});
}
}
The problem here is that you only display the HTML message if responseText is an empty string. You should get rid of the if statement:
if(responseText == 1) {
$('#response', form).html('<p class="message">Error...</p>');
} else {
$(form).fadeOut(500, function(){
form.html(msg).fadeIn();
});
}
This way the responseText is displayed. And I'm not 100% sure what your submission HTML looks like, but after you show the message you might want to fade out the "please wait" if it would still be visible after you hide the form.

Answer 2

Try to this way:
Make unique email column.
If the email address is already exist its return an error, and you can show the error message to user, on ajax error section.