[MYSQL] mysql_fetch_assoc() błędy Opcje

[gg1985]

Witam

Przy wykonywaniu takiego kodu:

[PHP] pobierz, plaintext 
<?php
$dbhost = "localhost";
$dbuser = "***";
$dbpassword = "***";
$dbdatabase = "phpbb_topics";
 
$db = mysql_connect($dbhost, $dbuser, $dbpassword);
mysql_select_db($dbdatabase, $db);
$sql = "select * from 'phpbb_topics' order by topic_id desc limit 1";
$wykonaj = mysql_query($sql);
$row = mysql_fetch_assoc($wykonaj);
echo $row;
?>
[PHP] pobierz, plaintext 

Dostaje taki błąd:

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource

Co robie źle ?