MyRules.php

<?php
// app/classes/myrules.php
class MyRules
{
    // note this is a static method
    public static function _validation_unique($val, $options)
    {       
        list($table, $field, $id) = explode('.', $options);
        
        $result = DB::select("LOWER (\"$field\")", 'id')
          ->where($field, '=', Str::lower($val))
          ->from($table)
          ->execute();
          
        if($result->count() > 0){
                   
          $data = $result->as_array();
                               
          return (empty($id)) ? false : ($data[0]['id'] == $id);
          
        }else{
          
           return true;          
        }       
    }

}