Odoo Help


This community is for beginners and experts willing to share their Odoo knowledge. It's not a forum to discuss ideas, but a knowledge base of questions and their answers.


Is there a way to set a value for a field for all existing records in the database at addon installation only?

Michael Karrer
on 8/11/15, 8:44 AM 896 views


  1. I have an existing Database with the model event.calendar.

  2. In this Database there are already a lot of records for calendar.event

  3. I install a new addon that extends the event.calendar model with a new field "category" with required=TRUE


Since the existing records do not hold any value for the new field the installation of the addon fails. Because the NOT NULL constrain could not be created since there are already records with NULL values for the new field. (Chicken Egg problem in some way)


Is there a way to set a default value for this new field but just for all existing records in the Database at module (addon) installation?


I do not want to set a permanent _default parameter for this field since after the installation is done the user should carefully set this field to a meaningful value.


Emipro Technologies Pvt. Ltd.

--Emipro Technologies Pvt. Ltd.--
Tiny ERP Pvt Ltd
| 6 7 8
Rajkot, India
--Emipro Technologies Pvt. Ltd.--

Being an emerging leader in IT market since 2011, Emipro Technologies Pvt. Ltd. has been providing a wide range of business solutions in Odoo & Magento. We are pleased to have a large pool of contented customers with our meticulous work in the domain of ERP & e-Commerce. A ray of relief & satisfaction to  our customers heart by our successful deployment in their organization, purely represents our success in Odoo platform. Hence, we take pride for being an Odoo partner with a vision of expanding our strategic alliances with our customers to offer them high value-added, trustworthy & cost effective solutions.


Since establishment, our business has span across 11 countries of the world. Our customers are companies of all sizes ranging from start-ups to large enterprises, who realize that they need a professional business solutions to generate revenue streams, establish proper communication channels or streamline business operations. Standing with strong determination of customer satisfaction, observing each minute detail of their business processes, providing proper guidance and moving forth to develop product accordingly adds our value and reliability among our customers. 


We are blessed with efficient, passionate & eclectic young developers who have come across almost all kinds of business profiles, working with full dedication, applying creativity & new features in existing modules and completing customer's projects successfully on predefined target. Our in-depth knowledge while giving business solutions in Odoo allows us to offer following services to our customers :


  • Consulting
  • Installation, Configuration & Customization
  • Training & Support
  • Maintenance
  • Upgradation
  • Documentation
  • Crafting community modules
  • Drafting videos on demand
  • Smart Apps development

We will be :) to welcome you @ www.emiprotechnologies.com to solve any kind of your business needs around Odoo. However we are just an inch away from you by email info@emiprotechnologies.com or a tweet to @EmiproTech

Emipro Technologies Pvt. Ltd.
On 8/11/15, 9:16 AM


To achieve your goal you need to define one method in your class where you add that new field. And set data into existing records. Please have a look on the below code.

class calendar_event(...)
    _inherit = "event.calendar"
    category_id = Fields.many2one(....)

    def _auto_init(self, cr, context=None):
        cr.execute("update event_calendar set category_id = 1 where category_id is null")

I hope it will resolve your issue.


Thank you! This was the method i was searching for!

Michael Karrer
on 8/11/15, 9:23 AM
Marvin Taboada
On 8/12/15, 12:04 AM

Michael, `_auto_init()` is an ORM method not expected to be completely redefined because it does important stuff during module initialization, please see:


You can safely override this method provided you also invoke the parent's class implementation as it is done in several models from the base module, e.g.:


    def _auto_init(self, cr, context=None):
        super(ir_attachment, self)._auto_init(cr, context)
        # Now safely perform your own stuff
        cr.execute('SELECT indexname FROM pg_indexes WHERE indexname = %s', ('ir_attachment_res_idx',))

The method I prefer for these cases is to add an `init(self, cr)` method on models. This method is invoked after `_auto_init()` provided it is defined in the model, see the following link for details about how both methods are invoked:


Have a nice day.

Thank you very much!

Michael Karrer
on 8/12/15, 2:17 AM

Your Answer

Please try to give a substantial answer. If you wanted to comment on the question or answer, just use the commenting tool. Please remember that you can always revise your answers - no need to answer the same question twice. Also, please don't forget to vote - it really helps to select the best questions and answers!

About This Community

This community is for professionals and enthusiasts of our products and services. Read Guidelines

Question tools

1 follower(s)


Asked: 8/11/15, 8:44 AM
Seen: 896 times
Last updated: 8/12/15, 10:38 AM