public function create(StudentDTO $student)
{
$connection = $this->db->getConn();
$exists = 'SELECT id FROM students LIMIT 1';
$isValid = $this->validate($_POST);
if ($isValid['state']) {
$sql = "INSERT INTO students(firstname, lastname, age, bday, email, sex, comment) VALUES ('" . $student->getFirstname() . "', '" . $student->getLastname() . "', '" . $student->getAge() . "', '" . $student->getBirthday() . "', '" . $student->getEmail() . "', '" . $student->getSex() . "', '" . $student->getAbout() . "')";
$result = $connection->query($sql);
if ($result !== true) {
echo mysqli_errno($connection) . ": " . mysqli_error($connection) . "\n";
}
}
return $isValid;
}