如何从mysql中提取登录的用户ID

Question

I'm trying to extract from users table the user id, but it doesn't work.

Login function:

function login($user, $password) {
$user = strip_tags(mysql_real_escape_string($user));
$password = strip_tags(mysql_real_escape_string($password));

$password = md5($password);

$sql = "SELECT * FROM users WHERE user = '$user' AND password = '$password'";
$result = mysql_query($sql) or die('Error. ' . mysql_error());


if (mysql_num_rows($result) == 1)
{
    $_SESSION['access']=true;
    $_SESSION["user"] = $user;
    $_SESSION["password"] = $password; 
    $_SESSION["id"] = $id;
    header('Location: '.DIR.'admin.php');
    exit;
}
else
{
    //error
    $_SESSION['error'] = 'Wrong name or password.';
}
}

Now when i'm logged in, i tried to post these info on admin.php with echo 'Username ' .$user. 'ID: ' .$id '; it doesn't show.

Answer 1

You should change line

if (mysql_num_rows($rezultat) == 1)

into

if (mysql_num_rows($result) == 1)

But definitely you should consider using PDO with prepared statements to prevent SQL injection or at least mysqli functions (mysql is deprecated now)