I am trying to create one field that can be accesses thru many odoo models,  Here is the model code!

# -*- coding: utf-8 -*-

from odoo import models, fields

class code_adi(models.Model):

    _inherit=['res.currency','res.partner','product.product']

     _order='adi_code asc'

    adi_code = fields.Char(string='Code')

    _sql_constraints = [

         ('name_uniq_code', 'UNIQUE (adi_code)', 'Code must be unique.')

]

when i upgrade my module with an xml file that is empty it works for me, and i am able to see the added field in all inherited models, but once i start inheriting views and trying to access my field ('adi_code'), i get an error saying that my field does not exist. 

Thanks