/**
  * @param $roleName
  * @return int
  */
 function getRoleId(string $roleName) : int
 {
     $db = SimpleDB::getInstance("conference_scheduler");
     $result = $db->prepare("SELECT id FROM roles WHERE name = ?");
     $result->execute([$roleName]);
     if ($result->affectedRows() === 0) {
         throw new \Exception("Role {$roleName} doesn't exist in the database.");
     }
     return intval($result->fetch()["id"]);
 }
 /**
  * @param int $userId
  * @return ProfileViewModel
  */
 function getUserInfo(int $userId) : ProfileViewModel
 {
     $db = SimpleDB::getInstance('conference_scheduler');
     $result = $db->prepare("SELECT\r\n                                username, email\r\n                                FROM users\r\n                                WHERE id = ?");
     $result->execute([$userId]);
     $userRow = $result->fetch();
     $user = new ProfileViewModel($userRow['username'], $userRow['email']);
     return $user;
 }