Preciso de ajuda com este código

[jacky167 0]

error
Warning: mysql_num_rows() expects parameter 1 to be resource, boolean
 

codigo

<?php
include('../include/db.php');
$fn = trim($_POST['fn']);
$ln = trim($_POST['ln']); 
$username = trim($_POST['username']); 
$password = md5(trim($_POST['password']));
if(strlen($fn) > 0 && strlen($ln) > 0 && strlen($username) > 0 && strlen(trim($_POST['password'])) > 0){
$check = mysql_query("SELECT * FROM users WHERE Username='$username' ",$con);
if(mysql_num_rows($check)==1){
echo '<p style="color: #9F6000;font-weight: bold;">Username is already taken. Try Different One.</p>';
}
else{
mysql_query("INSERT INTO users(First_Name,Last_Name,Username,Password) VALUES('$fn','$ln','$username','$password') ",$con);
if(mysql_error()==""){
echo '<p style="color: #4F8A10;font-weight: bold;">Registration Successful!</p>';
}
else{
echo '<p style="color: #D8000C;font-weight: bold;">Something Went Wrong, Try Again.</p>';
}
} 
}
else{
echo '<p style="color: #D8000C;font-weight: bold;">Please Fill All The Details.</p>';
} 
?>



O que estou fazendo de errado? 

[Gleyson Abreu 49]

Sua Query está com algum erro: 

$check = mysql_query("SELECT * FROM users WHERE Username='$username' ",$con);

Troque por:

$check = mysql_query("SELECT * FROM users WHERE Username='$username' ",$con) OR DIE(mysql_error());
$check = mysql_query("SELECT * FROM users WHERE Username='$username' ") OR DIE(mysql_error());

 

[jacky167 0]

5 minutos atrás, Gleyson Abreu disse:

Sua Query está com algum erro: 

$check = mysql_query("SELECT * FROM users WHERE Username='$username' ",$con);

Troque por:

$check = mysql_query("SELECT * FROM users WHERE Username='$username' ",$con) OR DIE(mysql_error());
$check = mysql_query("SELECT * FROM users WHERE Username='$username' ") OR DIE(mysql_error());

 

LOLLLL  Não recebo o erro e agora funciona, obrigado :)