logging.php

<?php
    include 'dbconnect.php';
        if(isset($_POST['login'])) {
            $email = $_POST['email'];
            $password = $_POST['password'];

            $email = mysqli_real_escape_string($connection, $email);
            $password = mysqli_real_escape_string($connection, $password);
            mysqli_query($connection,"SET NAMES 'utf8'");
            mysqli_query($connection,'SET CHARACTER SET utf8');
            $query = "SELECT * FROM users WHERE email = '{$email}'";
            $query_result = mysqli_query($connection, $query);
            if (!$query_result) {
                die("Error connection" . mysqli_connect_error($connection));
            }
            $result = mysqli_fetch_assoc($query_result);
            $user_id = $result['userId'];
            $user_name = $result['userFullName'];
            $user_email = $result['email'];
            $user_password = $result['password'];
            if ($email !== $user_email && $password !== $user_password) {
                header("Location: index.php");

            } else if ($email == $user_email && $password == $user_password) {
                $query_role= "SELECT * FROM users JOIN userhasrole ON users.userId=userhasrole.userId WHERE userhasrole.roleId = '{$user_id}'";
                $role_result = mysqli_query($connection,$query_role);
                $re=mysqli_fetch_assoc($role_result);
                if($re['roleId']== 1){
                    header("Location: admin.php");
                }elseif ($re['roleId']== 2){
                    header("Location: teacher.php");
                }else{
                    header("Location: student.php");
                }

            } else {
                header("Location: index.php");
            }

        }