Codeigniter provides select_sum method to get sum value in mysql table column. Writes a “SELECT SUM(field)” portion for your query. As with select_max(), You can optionally include a second parameter to rename the resulting field.
Let’s create a select_sum method in codeigniter
$this->db->select_sum('amount'); $result = $this->db->get('tbl_product')->row(); return $result->amount;