Admin and User PHP Database login

Question

I am pretty new to php coding and I have setup a working signup/signin system for a website, but now I want to create an admin user which can edit/upload pictures to the website. I just have no idea how to do it, so far I have just added a column to phpmyadmin which is usertype and its an enum with two variables which are admin and users, and I have set the default to user so when someone signs up they are defaulted as a user. so any help would be greatly appreciated.

This is my login php

if (isset($_POST['login-submit'])) {
    #
require 'dbh.inc.php';

$mailuid = $_POST['mailuid'];
$password = $_POST['pwd'];

if (empty($mailuid) || empty($password)) {
    header("Location: ../index.php?error=emptyfields");
    exit();

}else {
    $sql = "SELECT * FROM users WHERE uidUsers=?;";
    $stmt = mysqli_stmt_init($conn);
    if (!mysqli_stmt_prepare($stmt, $sql)) {
        header("Location: ../index.php?error=sqlerror");
        exit();
    }else{

        mysqli_stmt_bind_param($stmt, "s", $mailuid);
        mysqli_stmt_execute($stmt);
        $result = mysqli_stmt_get_result($stmt);
        if ($row = mysqli_fetch_assoc($result)) {
            $pwdCheck = password_verify($password, $row['pwdUsers']);
            if ($pwdCheck == false) {
                header("Location: ../index.php?error=wrongpassword");
        exit();
            }elseif ($pwdCheck == true) {
                session_start();
                $_SESSION['userId'] = $row['idUsers'];
                $_SESSION['userUid'] = $row['uidUsers'];

                header("Location: ../index.php?login=success");
                exit();

            }
        }
        else {
            header("Location: ../index.php?error=nouser");
        exit();
        }
    }

    }



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

This is my signup php

<?php
if (isset($_POST['signup-sumbit'])) {

    require 'dbh.inc.php';


    $username = $_POST['uid'];
    $email = $_POST['mail'];
    $password = $_POST['pwd'];
    $passwordRepeat = $_POST['pwd-repeat'];

    if (empty($username) || empty($email) || empty($password) || empty($passwordRepeat)) {
        header("Location: ../signup.php?error=emptyfields&uid=".$username."&mail=".$email);
        exit();
    }elseif (!filter_var($email, FILTER_VALIDATE_EMAIL) && !preg_match("/^[a-zA-Z0-9]*$/", $username)) {
        header("Location: ../signup.php?error=invaildmailuid");
        exit();
    }elseif (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
        header("Location: ../signup.php?error=invaildmail&uid=".$username);
        exit();
    }elseif (!preg_match("/^[a-zA-Z0-9]*$/", $username)) {
        header("Location: ../signup.php?error=invailduid&mail=".$email);
        exit();
    }elseif ($password !== $passwordRepeat) {
        header("Location: ../signup.php?error=passwordcheck&uid=".$username."&mail=".$email);
        exit(); 
    }else{
        $sql = "SELECT uidUsers FROM users WHERE uidUsers=?";
        $stmt = mysqli_stmt_init($conn);
        if (!mysqli_stmt_prepare($stmt, $sql)) {
            header("Location: ../signup.php?error=sqlerror1");
            exit();
        } else {
            mysqli_stmt_bind_param($stmt, "s", $username);
            mysqli_stmt_execute($stmt);
            mysqli_stmt_store_result($stmt);
            $resultCheck = mysqli_stmt_num_rows($stmt);
            if ($resultCheck > 0) {
                header("Location: ../signup.php?error=usertaken&mail=".$email);
                exit();
            } else {
                $sql = "INSERT INTO users (uidUsers, emailUsers, pwdUsers) VALUES (?, ?, ?)";
                $stmt = mysqli_stmt_init($conn);
                if (!mysqli_stmt_prepare($stmt, $sql)) {
                    header("Location: ../signup.php?error=sqlerror");
                    exit();
                    } else {
                        $hashedPwd = password_hash($password, PASSWORD_DEFAULT);


                        mysqli_stmt_bind_param($stmt, "sss", $username, $email, $hashedPwd);
                        mysqli_stmt_execute($stmt);
                        header("Location: ../signup.php?signup=success");
                        exit();
                    }




            }


        }



    }
    mysqli_stmt_close($stmt);
    mysqli_close($conn);


}else {
    header("Location: ../signup.php");
    exit();

}

This is a picture of the new column I added Picture of phpmyadmin

Answer 1

This is the code where you are checking if user has admin privileges and store in session

if($row['user_type'] == 'Admin'){
          $_SESSION['isAdmin'] = true;
}else{
          $_SESSION['isAdmin'] = false;
}

later you can use $_SESSION['isAdmin'] to give privileges as you wish

if($_SESSION['isAdmin']){
//code for uploading pictuers ..
}