Allow relation model changes

First off: great work, i really appreciate your effort!

I have a question regarding the migration of an existing database. I already read the UIDs section of the documentation but i think my case is a little bit different.

Lets say i have following schema, already filled with data:

building 1toN apartmens

and i'd like to add a new tier to my hierarchy like:

building 1toN level 1toN apartments

How can i make sure that my apartment data is accessible after an update?
I look for an easy solution like "on update add a default level between building and apartments".

Is this possible with objectbox? If yes, how?

Thank you.

从文档的 UIDs 部分以及本 issue 中描述的现有 schema 开始。确定 migration path 是否支持在建筑和公寓之间插入一层，同时保留现有的公寓数据；完成的标准是有一套有文档记录且受支持的操作步骤，或明确说明这是不可能的。