SQL not return database result

Question

I have a database with a "users" table. In users table I have following column:"user_id","user_first","user_last","user_email","user_phone","user_uid","user_password".

if (isset($_POST['submit'])) {
include 'dbh.inc.php';
$uid = $_POST['uid'];
$pwd = $_POST['password'];

if(empty($uid) || empty($pwd)) {
     header("Location: ../index.php?login=empty");
     exit();
} else {
    try {
        $sql    = "SELECT * FROM users";
        $result = $conn->prepare(
            $sql . "WHERE user_uid = ?"
        );
        $result->bindParam( 1, $uid, PDO::PARAM_STR );
        $result->execute();
    } catch (Exception $e) {
        echo"Bad Query";
    }
    $resultCheck = $result->rowCount();
    if ($resultCheck < 1 )  {
        header("Location: ../index.php?login_not_good");
        exit();
    } else {
        $row = $result->fetch(PDO::FETCH_ASSOC);
        if($row) {
            //De-hashing the password
            $hashedPwdCheck = password_verify($pwd,$row['user_password']);
            if ($hashedPwdCheck == false) {
                header("Location: ../index.php?login=error");
                exit();
            } elseif ($hashedPwdCheck == true) {
                //Log in the user here
                $_SESSION['u_id'] = $row['user_id'];
                $_SESSION['u_first'] = $row['user_first'];
                $_SESSION['u_last'] = $row['user_last'];
                $_SESSION['u_email'] = $row['user_email'];
                $_SESSION['u_uid'] = $row['user_uid'];  
                header("Location: ../index.php?login=login_success");
                exit();
               }
            }
        }
    }
} else {
    header("Location: ../index.php?login=error");
    exit();
}

The problem is when I try to login with my uid and password which has been created in sql database, It's return : "../index.php?login_not_good".What should I do?

Answer 1

As variant you can use named parameters

$sql = "SELECT * FROM users WHERE user_uid = :uid";
$result = $conn->prepare($sql);
$result->bindParam(':uid', $uid);
$result->execute();