PHP - MySQL WHERE not work - php

Question

When I add this code to my Php file
include "sql_connect.php";
$query_blog="SELECT * FROM messages";
$result_blog=mysql_query($query_blog);
$num_blog=mysql_numrows($result_blog);
mysql_close();
$sql_index_menu="0";
while ($sql_index_menu < $num) {
$msg_subject=mysql_result($result,$sql_index_menu,"subject");
$msg_id=mysql_result($result,$sql_index_menu,"id");
$msg_from=mysql_result($result,$sql_index_menu,"from");
$msg_to=mysql_result($result,$sql_index_menu,"recipient");
$msg_text=mysql_result($result,$sql_index_menu,"text");
$msg_time=mysql_result($result,$sql_index_menu,"time");
$msg_read=mysql_result($result,$sql_index_menu,"readed");
?>
<tr>
<td><?php if($msg_read == "0") {echo "<img src='/images/message.gif' width='32' height='32'>";} else {echo "<img src='/images/message.png' width='32' height='32'>";}?> <?php echo $msg_time; ?></td><td><?php echo $msg_subject; ?></td><td><?php echo $msg_from; ?></td>
</tr>
<?php
$sql_index_menu++;
}
everything work BUT, when i add this to $query_blog
$query_blog="SELECT * FROM messages WHERE recipent='$username'";
so it won't work..
I tryed to change $username with my name but it still not working.
This code is working, so I copyed it and still nothing...
include "sql_connect.php";
$query="UPDATE messages
SET readed='1'
WHERE id='$id'";
$result=mysql_query($query);
$num=mysql_numrows($result);
mysql_close();
include "sql_connect.php";
$query_blog="SELECT * FROM messages WHERE id='$id'";
$result_blog=mysql_query($query_blog);
$num_blog=mysql_numrows($result_blog);
mysql_close();
$msg_text=mysql_result($result_blog,$sql_index_blog,"text");
$msg_from=mysql_result($result_blog,$sql_index_blog,"from");
$msg_subject=mysql_result($result_blog,$sql_index_blog,"subject");
$msg_time=mysql_result($result_blog,$sql_index_blog,"time");
Can you help me?
I disabled login required to page so now you can see the page (sorry for language :D) As you can see, no error
The website

Answer 1

as mentioned there is a typo, you misstyped recipient, anyway - i recommend you to use mysql_error() function to debug you'r code, an example would be:
$result=mysql_query($query) or die("<b>error:</b>".mysql_error()."line:".__LINE__);

Answer 2

The easiest way to debug a code in PHP is using echo or print_r.
In this case, you can include echo on $query_blog after setting it and run the result in your mysql IDE (or mysql command line).
$query_blog="SELECT * FROM messages WHERE recipent='$username'";
echo $query_blog;
Also, it's not a good msyql practice using quotes on where because your code will be vulnerable to injections.
Instead, use this:
$result = sprintf("SELECT * FROM messages WHERE recipent='%s'", mysql_real_escape_string($username));
$result = mysql_query($query);
if (!$result) {
$message = 'Invalid query: ' . mysql_error() . "\n";
$message .= 'Whole query: ' . $result
die($message);
}

Answer 3

If you are querying a mysql database from php and you want to use php variables in your query you have to escape them, otherwise you are passing the string '$username', not the value that is stored in $username.
Does this work for you?
$query_blog="SELECT * FROM messages WHERE recipent='" . $username . "'";
var_dump($query_blog);