function addTeacher(Teacher $teacher)
{
$connectionObject = Connection::getInstance();
$connection = $connectionObject->get_connection();
$name_in_full = $teacher->getName();
$subject = $teacher->getSubject();
$address = $teacher->getAddress();
$telephone = $teacher->getPhoneNumber();
$registered_date = $teacher->getRegisteredDate();
$distance = $teacher->getDistance();
$school_id = $_SESSION['school_id'];
$stmt = $connection->prepare("INSERT INTO teacher (name_in_full, subject, address, telephone) VALUES (?,?,?,?)");
$stmt->bind_param("ssss", $name_in_full, $subject, $address, $telephone);
$result = $stmt->execute();
$stmt->close();
$teacher_id = mysqli_insert_id($connection);
$stmt = $connection->prepare("INSERT INTO teacher_school (teacher_id,school_id,start_of_working_date,distance_from_permanent_residence) VALUES (?,?,?,?)");
$stmt->bind_param("iisi", $teacher_id, $school_id, $registered_date, $distance);
$result = $stmt->execute();
$stmt->close();
return $result;
}