Hi guys,

After installed module base_address_city, I would like to create another field called District to have relationship Many2one to city_id (base_address_city)

My simple code:

(base_address_district.py)

...

class District(models.Model):

    _name = 'res.district'

    _description = 'District'

    _order = 'name'    

    name = fields.Char(String='District Name', required=True, translate=True, help='The full name of the district')

    zipcode = fields.Char("Zip")    

    city_id = fields.Many2one('res_city', 'City', required=True)

class Partner(models.Model):

    _inherit = ['res.partner']

    _name = 'res.partner'

    district = fields.Many2one('res.district', ondelete='restrict', string='district', index=True)

    @api.onchange('district_id')

    def _onchange_district_id(self):

        self.district = self.district_id.name

        self.zip = self.district_id.zipcode

        self.city_id = self.district_id.city_id

(base_address_district.xml)

...    
<record id="view_res_partner_extended_district_form" model="ir.ui.view">

        <field name="name">view_res_partner_extended_district_form</field>

        <field name="model">res.partner</field>

        <field name="inherit_id" ref="base.view_partner_form"/>

        <field name="arch" type="xml">

        <xpath expr="//field[@name='street2']" position="after">

        <field name="district" groups="base.group_no_one" placeholder="District..." />

        </xpath>

        </field>

        </record>

...

Then face the error:

...
psycopg2.ProgrammingError: relation "_unknown" does not exist
LINE 1: SELECT "_unknown".id FROM "_unknown" ORDER BY "_unknown"."id...

By searching internet, there is few ppl found similar issue while adding a module that have relationship with base module or res module for example:

https://www.odoo.com/forum/help-1/question/weird-error-programmingerror-relation-unknown-does-not-exist-line-1-select-unknown-id-from-unknown-order-by-unknown-id-74185

Please help to suggest if there is solution and reason behind.