[Web-development (jquery)] Username availability check using PHP and jQuery

Username availability check using PHP and jQuery

<?php /* CREATE TABLE IF NOT EXISTS `users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `username` varchar(150) NOT NULL, `email` varchar(100) NOT NULL', `pass` varchar(100) NOT NULL', PRIMARY KEY (`id`) ) */ //Username availability check using PHP and jQuery //if we got something through $_POST if (isset($_POST['user'])) { // here you would normally include some database connection include('db.php'); $db = new db(); // never trust what user wrote! We must ALWAYS sanitize user input $username = mysql_real_escape_string($_POST['user']); // build your query to the database $sql = "SELECT count(*) as num FROM users WHERE username = " . $username; // get results $row = $db->select_single($sql); if($row['num'] == 0) { echo 'Username <em>'.$username.'</em> is available!'; } else { echo 'Username <em>'.$username.'</em> is already taken!'; } } ?> <script> $(function() { $("#sub").click(function() { // getting the value that user typed var checkString = $("#username_box").val(); // forming the queryString var data = 'user='+ checkString; // if checkString is not empty if(checkString) { // ajax call $.ajax({ type: "POST", url: "do_check.php", data: data, beforeSend: function(html) { // this happen before actual call $("#results").html(''); }, success: function(html){ // this happen after we get result $("#results").show(); $("#results").append(html); } }); } return false; }); }); </script> <form action="do_check.php" method="post"> <input name="username" type="text" /> <input type="submit" value="Check" /> </form> 

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Posted by Jhoe XD