<?php
class AdminClass {
  protected $pdo = null;
  protected $host = 'localhost';
  protected $dbname = 'egitim';
  protected $username = 'root';
  protected $password = '';
  protected $charset = 'utf8';

  public function __construct() {
    try {
      $this->pdo = new PDO("mysql:host=$this->host;dbname=$this->dbname;charset=$this->charset", $this->username, $this->password );
    } catch (\Exception $error) {
      die($error->getMessage());
    }
    if (!isset($_SESSION['mail']) && !isset($_SESSION['login'])) {
      header('Location: ./login.php');
    }
  }

  // Sorgu Kodu
  public function pdoQuery($sql)
  {
    $query = $this->pdo->query($sql, PDO::FETCH_ASSOC)->fetchAll();
    if ($query) {
       return $query;
     } else { return false; }

  }

  public function getSecurity($data) {
      if (is_array($data)) {
        $variable = array_map('htmlspecialchars', $data);
        $response = array_map('stripslashes',$variable);
        return $response;
        // code...
      } else {
        $variable = htmlspecialchars($data);
        $response = stripslashes($variable);
        return $response;
      }
  }

  }
 ?>

<?php
Veri Ekleme Kodu ;
if (isset($_POST['save'])){
    if ($_POST['save'] == 1001) {
        $degisken_fiili_sirket  = $_POST['formdangelen_fiilisirket'];
        $sql = "INSERT INTO db_personel_kisiselbilgiler  (fiili_sirket_adi) VALUES (?)";
        $args = [$degisken_fiili_sirket];
        $result = $adminclass->getSecurity($args);
        print $adminclass->pdoInsert($sql,$result);
    }
}
?>

               <form class="form-horizontal card"  method="POST" >
                        <div class="card-body">
                            

                            <!-- Fiili Çalıştığı Şirket -->
                            <div class="row mb-4">
                                <label class="col-md-3 form-label">Fiili Çalıştığı Şirket</label>
                                <select name="formdangelen_fiilisirket" class="form-control select2 form-select col-md-9" data-placeholder="Fiili Şirket Seçiniz.">
                                    <option label="Seçiniz">
                                    </option>
                                    <?php
                                    $sql = "SELECT * FROM fiilisirketadi ORDER BY fiilisirketadi ASC";
                                    $variable = $adminclass->pdoQuery($sql);
                                    if ($variable != false) { foreach ($variable as  $value) {
                                        $db_f_sirket_adi = $value['fiilisirketadi'];
                                        ?>

                                    <option value="<?php echo $db_f_sirket_adi; ?>">
                                        <?php print $db_f_sirket_adi; ?>
                                    </option>
                                    <?php } } ?>
                                </select>
                            </div>

                                <!-- Gönder butonu-->
                                <div align="right">
                                    <input type="submit" class="btn btn-success btn-pill">
                                    <input type="hidden" name="save" value="1001"></input>
                                </div>

                        </div>
                            </form>