Modifying GeneratedFields is not supported - not documented under model field reference for GeneratedField

[ldeluigi]

When I attempted to migrate an alteration of a db-persisted GeneratedField, I got the ValueError:
Modifying GeneratedFields is not supported - the field XYZ must be removed and re-added with the new definition.

I couldn't find help nor hint for that in the documentation, especially under the model field reference for GeneratedField.

I'd like to see that documented, if possible with help for workarounds

[Mariusz Felisiak]

Thanks for this ticket, however, raised exception is clear and it contains a hint: "must be removed and re-added". Modifying GeneratedFields is not possible in most cases, and even if it's, it still has many db-specific restrictions. This is not something that we want to support and workaround doesn't exists. It's not worth documenting.

[Simon Charette]

Not saying we should take any action or revisit supporting recreating generated fields (making alter do an implicit remove + add) but ​I found it interesting that PostgreSQL was planning to add support for it in 17 through a non-standard SQL extension.