need some help with a log in

[makka]

hello ive been making a basic login just to expand my knowledge a little this is my page that deals with my login but ive come to a hump in the bridge.. i get a error with this page

<?php
if (isset($_POST['submit'])) {
include('config.php');
$query = "SELECT * FROM `users` WHERE username='".$_POST["username"]."' AND password='".md5($_POST["password"])."' LIMIT 1";
mysql_query($query) or die(mysql_error());
if (mysql_num_rows($query) != 1) { die("You have entered an invalid username or password."); }
else { echo 'it worked'; }
}
?>

 

the error is

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in C:\Program Files\xampp\htdocs\x\php+mysql\reg\login.php on line 6

so whats up here also what i don't get now is how do i know which user is which once they are logged in lets say i log in and its just a simply script that will redirect me to ball.php

 

every time i click a this one link i will get one more number added to the msql db if i have a column called num in the db

 

if you try to go to ball.php with out being logged in it will redirect you to the index page simple??

[xenophobia]

Wrong parameter had been sent...

You should do this

$sql = "SELECT .......";
$query = mysql_query($sql) or die(mysql_error());

if(mysql_num_rows($query) != 1){
.
.
.
}

[tauchai83]

<?php
if (isset($_POST['submit'])) {
include('config.php');
$query = "SELECT * FROM `users` WHERE username='".$_POST["username"]."' AND password='".md5($_POST["password"])."' LIMIT 1";

$result=mysql_query($query) or die(mysql_error());

if (mysql_num_rows($result) < 1) { die("You have entered an invalid username or password."); }
else 
{ echo 'it worked'; 
}
}
?>

try this out. cheerss

[makka]

tauchai83

 

worked lovley now for my other question

[makka]

b 2 the u 2 the m 2 the p