save-user-data.php

<?php

if (!empty($_POST['name']) && !empty($_POST['email']) && !empty($_POST['phone']) && !empty($_POST['type'])) {

  $name = trim(filter_var($_POST['name'], FILTER_SANITIZE_STRING));
  $email = trim(filter_var($_POST['email'], FILTER_VALIDATE_EMAIL));
  $phone = trim(filter_var($_POST['phone'], FILTER_SANITIZE_STRING));
  $type = trim(filter_var($_POST['type'], FILTER_SANITIZE_STRING));
  $phoneRegExp = "/^0[2-9]\d{7,8}$/";
  $type_kinds = ['basic', 'business', 'free'];

  if (mb_strlen($name) > 1 && mb_strlen($name) < 70) {

    if ($email) {

      if (preg_match($phoneRegExp, $phone)) {

        if (in_array($type, $type_kinds)) {

          $dbcon = 'mysql:host=localhost;dbname=eshop;charset=utf8';
          $db = new PDO($dbcon, 'root', '');
          $sql = "INSERT INTO contact_log VALUES(null,?,?,?,NOW())";
          $query = $db->prepare($sql);

          if ($query->execute([$name, $email, $phone])) {
            echo true;
          }
        }
      }
    }
  }
}