显示数据库php oop中的所有用户

Question

I'm trying to display all users from my db using php oop. I really don't know how to include the user.php into connectionFile.php or something that might work.my code: user.php:

    public class User{
    protected $firstname;
    protected $lastname;
    protected $email;
    protected $password;
    protected $age;
    protected $role;
    protected $file;
    protected $db;

    public function __construct($DB_con){
       $this->db = $DB_con;
    }

    public function __construct($firstname, $lastname, $email){
        $this->firstname = $firstname;
        $this->lastname = $lastname;
        $this->email = $email;
    }

    public function getFirstname(){
        return $this->firstname;
    }
    public function getLastname(){
        return $this->lastname;
    }
    public function getEmail(){
        return $this->email;
    }

    public function setFirstname($firstname){
        $this->firstname = $firstname;
    }
    public function setLastname($lastname){
        $this->lastname = $lastname;
    }
    public function setEmail($email){
        $this->email = $email;
    }
    public function getAllUsers(){
        try{
            $stmt = $this->db->prepare("select * from user");
            $stmt->execute();
            return $stmt;

        }catch(PDOException $e){
            echo $e->getMessage();
        }
    }
   }

My connectionFile.php:

require_once ("user.php");
// session_start();
$servername = "localhost";
$username = "root";
$password = "root";
$database = "first_project";
try {
    $conn = new PDO("mysql:host=$servername;dbname=first_project", $username, $password);
    // set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
   // echo "Connected successfully"; 
 }
 catch(PDOException $e){
    echo "Connection failed: " . $e->getMessage();
 }

and my displayResult.php(I also have a page html with the form):

 <?php
 require_once("connectionFile.php");
 //include_once 'user.php';
 if(isset($_POST['button'])){
    //$user = new User();
    echo "skksksks";
 }
 else{
    echo "v";
 }

?>

the button is working, I want in the button post to call the function getAllusers from user class but I really don't know how because every time I try to include that file anywhere it gives me page not found.

Answer 1

You can create the object of your class to access the methods.

require 'user.php';
$obj=new User($db_con);
$obj->setFirstName('test');

and so on...

And please make sure can you overload constructor in php... I do not think so..