Add sequential number in database, that resets every year - php

Question

I am building a project using Codeigniter + MySQL + Active Record.
In my MySQL db i have a table named Requests with columns protocol,year and some other columns where i store general information of a request (like title, subject etc...), nothing special to mention.
Protocol and year are TYPE INT and must be auto generated like below.
Every year, at 01/01/XXXX-00:00:00 the protocol field must reset to number 1 (the first request saved after 01/01/XXXX, must have protocol value 1) and for the upcoming requests, increase it sequentially by 1, until next year and so on.
To reset the protocol, i will add a cron in a later phase where i will do a trick to reset. Still don't know how.
What i need to do now:
Whenever i add a new request, the protocol of the new row must be increased by 1.
Pseudocode:
new_protocol = previous_protocol + 1
What i am doing so far
I have a function in my model which Inserts a new request, but so far i do nothing about the protocol number, i enter it manually through my form.
public function addRequest($request) {
$this->db->insert('requests', $request);
if ($this->db->affected_rows() == 1)
return $this->db->insert_id();
return FALSE;
}
What is the most efficient way to achieve this?
Should i find the last protocol number in my Controller -> add 1 -> send to model to add?
Should i find the LAST and MAX protocol number in model -> add 1 -> insert to db?
Something else?
Any ideas will be appreciated.

Answer 1

I'd approach like so:
add column ID in your table and set it to auto-increment
php - set the default timezone to use (since PHP 5.1): date_default_timezone_set('UTC');
php - get current year: $cyear=date("Y");
get row max(ID) and compare if the stored year has changed compared to $cyear
if it has changed and following your pseudocode example:
new_protocol = 1
otherwise
new_protocol = previous_protocol + 1

Answer 2

Ok so i created a library in Codeigniter and wrote 2 functions, 1 in Library and 1 in Model.
Library
public function getProtocolNumber() {
$CI = &get_instance();
$year = date('Y');
$max_protocol = $CI->request_model->getYearsProtocol($year);
$max_protocol = $max_protocol['max_protocol_number'];
if ($max_protocol && !empty($max_protocol) && $max_protocol != NULL) {
$protocol_number = (int) $max_protocol + 1;
} else {
$protocol_number = 1;
}
return $protocol_number;
}
Model
public function getYearsProtocol($year) {
$qry = $this->db->select('MAX(protocol_number) as max_protocol_number')
->from('requests')
->where('protocol_year', $year)
->get();
if ($qry->num_rows() > 0)
return $qry->row_array();
return FALSE;
}