PHP 和 ORACLE 选择登录数据

Question

I have problem with my login page where it keep showing the alert wrong username/password combination when I try to login but there is no error shown. I have read other stackoverflow questions but still don't understand what is the problem.

Here is my code

if (isset($_POST['login_user'])) {
  $username = $_POST['username'];
  $password = $_POST['password'];

    $query = "SELECT * FROM student WHERE stud_id='$username' AND stud_password='$password'";
    $results = oci_parse($db, $query);

    oci_execute($results);
    if (oci_num_rows($results) == 1) {

      $row = oci_fetch_assoc($results);

      $_SESSION['fullname'] = $row['stud_name'];
      $_SESSION['username'] = $username;
      //header('location: adminDash.php');

      echo
            (
                "<SCRIPT LANGUAGE='JavaScript'>
                window.alert('Login Succesfull!')
                window.location.href='testing.php'
                </SCRIPT>"
            );
    }
    else {
      echo
            (
                "<SCRIPT LANGUAGE='JavaScript'>
                window.alert('Wrong username/password combination!')
                </SCRIPT>"
            );
    }
}

Answer 1

<?php
require "connection1.php";
    session_start();
    if(isset($_POST['submit'])){ 

        if(count($_POST)>0) {
            $myusername =$_POST['email'];
            $mypassword =$_POST['password'];

            $query = oci_parse($connection,"SELECT * FROM c_l_t_login WHERE c_l_t_email='".$myusername."' and c_l_t_password='".$mypassword."'");
            //$vtpid = oci_parse($connection, $query);
            oci_execute($query);
            $row = oci_fetch_assoc($query);

            if(is_array($row)) {
    
                $_SESSION["id"] = $row['c_l_t_id']; 
                $_SESSION["email"] = $row['c_l_t_email'];
                //$_SESSION["name"] = $row['name'];
                            echo
                                (
                                    "<SCRIPT LANGUAGE='JavaScript'>
                                    window.alert('Login Succesfull!')
                                    window.location.href='index.php'
                                    </SCRIPT>"
                                );   
            }else{
                            echo
                            (
                                "<SCRIPT LANGUAGE='JavaScript'>
                                window.alert('Wrong username/password combination!')
                                </SCRIPT>"
                            );

        }
    }
?>