Add-on updates and data migration

The data model you choose when writing an add-on module might turn out to have some weaknesses, so you may need to adjust it during the life cycle of your add-on module. In order to allow that without a lot of hacks, Odoo supports versioning in add-on modules and running migrations if necessary.

How to do it...

We assume that in an earlier version of our module, the date_release field was a character field, where people wrote whatever they saw fit as the date. We now realize that we need this field for comparisons and aggregations, which is why we want to change its type to Date.

Odoo does a great job at type conversions, but, in this case, we're on our own, which is why we need to provide instructions as to how to transform a database with the previous version of our module installed on a database where the current version can run. Let's try this with the following steps:

1. Bump the version in your __manifest__.py file:

   &...