PHP login script always returns "login failed" - php

Question

I have to give users the ability to log in for an assignment. At first, it seemed to me this script was simple enough to work, but everytime I try to log in with an existing account it gives me the "login failed" message. I don't know where my mistake lies. It's a PostgreSQL database, I'll enclose an image of it below.
<?php
require 'databaseaccess.php';
try {
$conn = new PDO('pgsql:host=' . DB_HOST . ';dbname=' . DB_NAME, DB_USERNAME,DB_PASSWORD);
} catch (PDOException $e) {
print "Error: " . $e->getMessage() . "\n";
phpinfo();
die();
}
$username = $_POST['username'];
$password = $_POST['password'];
$tablename = "users";
// sql-injection counter
$username = stripslashes($username);
$password = stripslashes($password);
$username = mysql_real_escape_string($username);
$password = mysql_real_escape_string($password);
$qry = $conn->prepare("SELECT * FROM $tablename WHERE userid = :username and userpass = :password");
$qry->bindParam(':username', $username, PDO::PARAM_STR, 16);
$qry->bindParam(':password', $password, PDO::PARAM_STR, 16);
$qry->execute();
$result = pg_query($qry);
$count = pg_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row
if ($count == 1) {
$_SESSION['loggedin'] = true;
$_SESSION['username'] = $username;
header("location:logingelukt.php");
} elseif ($count = -1) {
echo "there has been an error";
} else{
print $count;
echo "login failed";
}
?>
I have no problems connecting to the database, so that's not an issue, it's just that it always sees $count as something else than zero. Another oddity is that the print $count command doesn't output anything.I use the account I made with postgresql outside of the page, which is just admin:admin. Also, I'm sure the right variables are getting passed from the form.
EDIT: After using var_dump($result), as advised by kingalligator, it seems that $result is indeed NULL, thus empty. I'm gonna try using fetch() instead of pg_query().

Answer 1

I think the issue is that you're mixing PDO and pg_ functions.
Replace:
$result = pg_query($qry);
$count = pg_num_rows($result);
With:
$result = $qry->fetchAll();
$count = count($result);
PDO Function reference can be found here: http://www.php.net/manual/en/class.pdostatement.php

Answer 2

Have you confirmed that you're actually getting data returned from your query? Try this:
var_dump($result);
To ensure that data is being returned from your query. You can still have a successful connection to a database, yet have a query that returns nothing.

Answer 3

You probably should check your column userid at WHERE clause. I don't know the table columns, but is strange that 'userid' has the name of the user in:
"SELECT * FROM $tablename WHERE userid = :username and userpass = :password"
Maybe it is causing the problem.