how to generate Custom id in codeigniter

Code:

$cc = $this->db->count_all('job_card');
$coun = str_pad($cc,4,STR_PAD_LEFT);
$id = "JI"."-";
$d = date('y') ;
$mnth = date("m");
$customid = $id.$d.$mnth.$coun;

Help me: I am generating "JI-18051000" This id. But i need "JI-18050001" this id.

Code:

$cc = $this->db->count_all('job_card');
$coun = str_pad($cc,4,STR_PAD_LEFT);
$id = "JI"."-";
$d = date('y') ;
$mnth = date("m");
$customid = $id.$d.$mnth.$coun;

Help me: I am generating "JI-18051000" This id. But i need "JI-18050001" this id.

Do you have id in job_card table? if so get 

PHP Code:

$result = $this->db->select('max("id") as max_id', false)->from('job_card')->get(); $coun = $result['max_id'] + 1; 


 and if your generated id is final value just generate new column in your job_card table and record it there so that you won't regenarate every time.
You can also take look at "composite fields" for your db

$cc = $this->db->count_all('gbp')+1;
$coun = str_pad($cc,4,STR_PAD_LEFT);
$coo=strrev($coun);
$id = "GBP"."-";
$d = date('y') ;
$mnth = date("m")."-";
$product_id = $id.$d.$mnth.$coo;
echo $product_id;