Document how to update ClassName references if changing the name of a DataObject class

[sunnysideup]

Affected Version

All versions

Description

When a DataObject ClassName is changed the SS project may not work anymore as there may be unexpected references to the classname in the database tables.

Unexpected as: not the main ClassName field in the table relating to the class itself, but references in other tables (including Foo_Versions).

Proposed solution

Use the concepts from this module: https://github.com/sunnysideup/silverstripe-search-all-tables-and-fields and keep a log of changes made.

Question

This may already be covered by:

---
Name: project
---
SilverStripe\ORM\DatabaseAdmin:
  classname_value_remapping:
    Building: 'Project\Web\Models\Building'
    City: 'Project\Web\Models\City'

Although I am not sure if it would fix all mentions.

[michalkleiner]

I believe the DatabaseAdmin::classname_value_remapping config already provides this for ORM-created db columns. Anywhere else it's project-level code.

[GuySartorelli]

Yeah this functionality definitely already exists. I'd say it should be documented though, I couldn't find anything in the docs when I looked briefly just now.
I'll move this to the developer-docs repo.