MySQL Count功能无法正常工作

Question

$req_user = trim($_GET['user']);
    mysql_connect("$host", "$username", "$password")or die("cannot connect");
    mysql_select_db("$db_name")or die("cannot select DB");
$get_data = "SELECT * FROM `users` WHERE uname = '$req_user'";
$result = mysql_query($get_data) OR die(mysql_error());
$rows = mysql_fetch_assoc($result);
$email = $rows['email'];
$gravatar = md5(strtolower(trim("$email")));
$user_likes = mysql_query("SELECT COUNT(*) FROM likes WHERE username = '$email'");

I'm trying to count all of the rows in the database likes with the email of the current user in their username field.
(It's a loop to get info from links like userinfo.php?user=xxx.)
When I echo $user_likes there is no output.

What is wrong with the code?
http://www.tutorialspoint.com/mysql/mysql-count-function.htm

Answer 1

Assuming that $gravatar = md5(strtolower(trim("$email"))); is not related to the question here and not needed, you could also use one query to the database, to get the count:

$req_user = trim($_GET['user']);
mysql_connect("$host", "$username", "$password") or die("cannot connect");
mysql_select_db("$db_name") or die("cannot select DB");
$get_count_query = 
    "SELECT COUNT(*)
     FROM likes 
     WHERE username = 
           ( SELECT email
             FROM users 
             WHERE uname = '$req_user'
           )
    ";
$result = mysql_query($get_count_query) or die(mysql_error());
$row = mysql_fetch_row($result);
$user_likes = $row[0];