having problems checking username availability

Question

I have a code here that will check if a username is available but I am getting a error message stating this:

 <br /> <b>Warning</b>: mysql_result() expects parameter 1 to be resource, boolean  given in <b>C:\xampp\htdocs\username_check.php</b> on line <b>8</b><br />     $username_result

I searched stackoverflow and found a few similar questions but none of them help.

my first php code is this:

<?php

mysql_connect('localhost','username','password');
mysql_select_db('logins');


?>

my second php code is this:

require 'db_connect.php';
if (isset($_POST['username'])) {
$username = mysql_real_escape_string($_POST['username']);
if (!empty($username)) {
  $username_query  = mysql_query ("SELECT COUNT('id') FROM 'users' WHERE   'username'='$username'");
  $username_result = mysql_result($username_query, 0);

  }
}
?>

and my jquery is this:

jQuery( '#box1' ).keyup(function(){
var username = jQuery(this).val();

jQuery( '#msg_out1' ).html('<img src="/img/ajax-loader.gif" width="43" height="11" /> &nbsp; Checking availability... ');

 if (username != '') {
 jQuery.post('/click/username_check.php', { username: username }, function(data){
    jQuery( '#msg_out1').text(data);

 });
 }else {
 jQuery( '#msg_out1' ).html('Choose a Username.').css('color','grey').css('font-  size','15px').css('margin-left','40px');
 }
   });
 });

I use jQuery instead of $ because i specified at the top before document ready a jQuery no conflict code.

mysql_* functions have been deprecated as of PHP 5.5.0. Use PDO or mysqli_* instead! Personally, I would recommend PDO: http://php.net/manual/en/book.pdo.php — Patrick Geyer, Dec 08 '13 at 23:08
It's likely your `mysql_query` call is returning false (failing) - hence the error. You might have trouble getting decent replies out of people while using `mysql_*`. — scrowler, Dec 08 '13 at 23:12
Use `mysqli` unless you want to change all your code when your Server is updated. — StackSlave, Dec 09 '13 at 00:02
actually not very obvious or you would have found an answer already — charlietfl, Dec 09 '13 at 01:56
The answers I found were irrelevant, I search for answers before asking for help — user3052886, Dec 09 '13 at 02:11

score 0 · Answer 1 · answered Dec 08 '13 at 23:14

Generally this message

mysql_result() expects parameter 1 to be resource

Means that your query has a syntax error and has failed (this is not the same as a successful query returning 0 rows). Looking at your query you have a lot of single quotes. That could be your problem. Try this instead (I added concatenation because it improves readability)

mysql_query("SELECT COUNT(id) FROM `users` WHERE `username`='" . $username . "'");

StackSlave · Answer 2 · 2013-12-09T00:29:31.997

Personally I would do the following:

// db_connect.php - keep in folder named restricted
// a function makes it easy to create a new instance without using agrs again
<?php
function db(){
  return new mysqli('localhost', 'username', 'password', 'database');
}
?>

// username_check.php - you may keep in folder click
<?php
require 'restricted/db_connect.php'; $db = db();
if(isset($_POST['username'])){
  $username = $db->real_escape_string($_POST['username']);
  if(!empty($username)){
    $username_query  = $db->query("SELECT COUNT('id') FROM users WHERE username='$username'");
    if($username_query->num_rows > 0){
      $r = '';
      while($row = $username_query->fetch_row()){
        $r = $row[0];
      } 
      echo $r;
    }
    else{
      echo '';
    }
    $username_query->free(); $db->close();
  }
}
?>

Also, your jQuery should look more like:

$('#box1').keyup(function(){
  var username = $(this).val(), msgO = $('#msg_out1');
  msgO.html('<img src="/img/ajax-loader.gif" width="43" height="11" /> &nbsp; Checking availability... ');
  $.post('/click/username_check.php', {username: username}, function(data){
    if(username !== ''){
      msgO.text(data);
    }
    else{
      msgO.html('Choose a Username.').css('color','grey').css('font-  size','15px').css('margin-left','40px');
    }
  });
});
// use `$.noConflict()` if `$` is a problem

You forgot that jQuery is Asynchronous.

Not quite. `mysqli_query` does require the connection be passed but the older [mysql_query](http://us3.php.net/manual/en/function.mysql-query.php) function does not (will use the last connection made). Still, it's better to use `mysqli` but I answered it within the context of the OP — Machavity, Dec 09 '13 at 00:10

having problems checking username availability

2 Answers2