CodeIgniter 3 - joint data from another table - php

Question

Original function:
function getRows($id = ""){
if(!empty($id)){
$query = $this->db->get_where('orders', array('id' => $id));
return $query->row_array();
}else{
$query = $this->db->get('orders');
return $query->result_array();
}
}
I need to JOIN data from table order_shipping and order_products where order_id = order_id
I do:
/*
* Fetch user data
*/
function getRows($id = ""){
if(!empty($id)){
$query = $this->db->get_where('orders', array('id' => $id));
return $query->row_array();
}else{
$this->db->select('*');
$this->db->from('orders');
$this->db->join('order_shipping', 'orders.id = order_shipping.id');
$this->db->join('order_products', 'order_shipping.id = order_products.id');
$query = $this->db->get('');
return $query->result_array();
}
}
This above code working correct. But currently JOIN only after else. I need do the same way before else:
* Fetch user data
*/
function getRows($id = ""){
if(!empty($id)){
$this->db->select('*');
$this->db->from('orders');
$this->db->join('order_shipping', 'orders.id = order_shipping.id');
$this->db->join('order_products', 'order_shipping.id = order_products.id');
$query = $this->db->get('', array('id' => $id));
return $query->row_array();
}else{
$this->db->select('*');
$this->db->from('orders');
$this->db->join('order_shipping', 'orders.id = order_shipping.id');
$this->db->join('order_products', 'order_shipping.id = order_products.id');
$query = $this->db->get('');
return $query->result_array();
}
}
But this code before else not working correct for me and currently display wrong data. When I try fetch all orders, then second function display correct all orders. But when I try fetch example only order ID 2, then is used first function and display wrong data, example when I fetch order ID2, then always display only order with ID 1.
This function is for REST API fetch orders.