Hi community

I have been testing some variants to achieve the described goal, but there is not a simple way to set custom ID on Odoo, and the One2Many realtionship don't work form me without the direct Many2One relation.

I have solved this using triggers in PostgreSQL database. I have modified the models making some modifications to the generated model to inject the trigger. For example:

class Sample(models.Model):
    _name = "sample"
    _description = "Ejemplo"

    rid = fields.Integer(
        "ID de referencia", required=True, index=True, unique=True)
    name = fields.Char("Nombre")
    ...

    def init(self):
        cr = self._cr
        cr.execute('CREATE OR REPLACE FUNCTION id_sample() RETURNS trigger AS $id_sample$ '
               ' BEGIN '
               ' NEW.id := NEW.rid; '
               ' RETURN NEW; '
               ' END; '
               ' $id_sample$ LANGUAGE plpgsql; ')
        cr.execute('DROP TRIGGER IF EXISTS trg_sample on sample')
        cr.execute('CREATE TRIGGER trg_sample '
               ' BEFORE INSERT ON sample '
               ' FOR EACH ROW '
               ' EXECUTE PROCEDURE id_sample()')

I hope this can help other users.