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 id="username_box" class="search_box" name="username" type="text" />
<input id="sub" type="submit" value="Check" />
</form>
