如何在PHP中为管理员和用户分别登录？

Question

I'm a student and I want to explore more on PHP. I try using functions but I have issues that I dont understand. I want a separated login for the admin and user but always takes me to the first if statement.

            <?php
            session_start();

            $connect = mysqli_connect('localhost','root','');

                if (!$connect){

                        die ("Unable to connect ".mysqli_connect_error($connect));
                        exit();
                } 
                if (!mysqli_select_db($connect,'gram')) {

                    die ("Unable to select ".mysqli_error($connect));
                    exit();
                }


            $email = $_POST['email'];
            $password = $_POST['password'];
            $adminemail = "[e-mail]";
            $adminpass = "gram123";

            function loginUser(){
                global $connect, $email, $password;
                $statement = mysqli_prepare($connect, "SELECT * FROM tbl_users WHERE email=? AND password=? LIMIT 1"); 
                    mysqli_stmt_bind_param($statement, "ss", $email, $password);
                    mysqli_stmt_execute($statement);
                    mysqli_stmt_store_result($statement);
                    $count = mysqli_stmt_num_rows($statement);
                    mysqli_stmt_close($statement); 
                    if ($count < 1){
                        return true; 
                    }else {
                        return false; 
                    }   
            }

            function loginAdmin(){

                global $connect, $adminemail, $adminpass;
                $statement = mysqli_prepare($connect, "SELECT * FROM tbl_gramusers WHERE email=? AND password=? LIMIT 1"); 
                    mysqli_stmt_bind_param($statement, "ss", $adminemail, $adminpass);
                    mysqli_stmt_execute($statement);
                    mysqli_stmt_store_result($statement);
                    $count = mysqli_stmt_num_rows($statement);
                    mysqli_stmt_close($statement); 
                    if ($count < 1){
                        return true; 
                    }else {
                        return false; 
                    }
            }

            if(loginUser()){
                header('Location:../index.html');
            }   
            if (loginAdmin()){
                header('Location:../admin.html');
            }



            ?>

Answer 1

In both function change

$count < 1

to

$count == 1

If in DB it matches a record and have one row then it should return true else false.

In current scenario if no rows found it returns 0 and you condition satisfies it $count < 1 so it will always return true and first IF will execute only.

Also, you can write the code is much better way like

function login($tableName){
   global $connect, $email, $password;
   $query = "SELECT * FROM ". $tableName ." WHERE email=? AND password=? LIMIT 1"
   $statement = mysqli_prepare($connect, $query); 
   mysqli_stmt_bind_param($statement, "ss", $email, $password);
   mysqli_stmt_execute($statement);
   mysqli_stmt_store_result($statement);
   $count = mysqli_stmt_num_rows($statement);
   mysqli_stmt_close($statement); 
   return ($count == 1);
 }


// Calling function to check login for admin and user

   if(login('tbl_users')){
      header('Location:../index.html');
   } else if (login('tbl_gramusers')){
      header('Location:../admin.html');
   } else {
     echo 'Wrong Username or password!';
   }