如何在PHP的代码中MD5哈希密码？

Question

我想以正确的方式从登录表单中获取密码。到目前为止，我还没有成功。由于他随后将哈希视为数据库中的密码，因此无法获取普通密码。有人可以帮我吗？

这是我的代码：

<?php
session_start();

  if (isset($_POST['login'])) {
    if (isset($_POST['username']) && isset($_POST['password'])) {
      include_once("../include/dbcon.php");

      $username = $_POST['username'];
      $password     = $_POST['password'];
      $stmt = $conn->prepare("SELECT * FROM personeelsgegevens WHERE Personeelsnummer = :Personeelsnummer AND Voucher = :Voucher");
      $stmt->bindParam(":Personeelsnummer", $username);
      $stmt->bindParam(":Voucher", $password);
      $stmt->execute();

      if ($stmt->rowCount() == 1){
        if($r = $stmt->fetch(PDO::FETCH_ASSOC)){
          echo "<script>alert('Succesvol ingelogd'); window.location='../php/activiteiten.php'</script>";
          $_SESSION["id"]   = $r['Personeelsnummer'];
          $_SESSION["rol"]  = "personeel";
          exit();
        }
      }else {
        $stmt = $conn->prepare("SELECT * FROM users WHERE user_name = :user_name AND password = :password");
        $stmt->bindParam(":user_name", $username);
        $stmt->bindParam(":password", $password);
        $stmt->execute();
          if ($stmt->rowCount() == 1){
            if($r = $stmt->fetch(PDO::FETCH_ASSOC)){
            echo "<script>alert('Succesvol ingelogd als admin'); window.location='../php/admin.php'</script>";
            $_SESSION["id"]   = $r['gebruikersID'];
            $_SESSION["rol"]  = "admin";
            exit();
          }
        } else {
          echo "<script>alert('Niet juist ingelogd check je gebruikersnaam en/of wachtwoord'); window.location='../php/inloggen.php'</script>";
          exit();
        }
      }

    }else {
      echo "<script>alert('Niet juist ingelogd check je gebruikersnaam en/of wachtwoord'); window.location='../php/inloggen.php'</script>";
      exit();
    }
  }else {
    echo "<script>alert('Niet juist ingelogd check je gebruikersnaam en/of wachtwoord'); window.location='../php/inloggen.php'</script>";
    exit();
  }
 ?>