核心数据：从3个实体中提取对象到一个实体中并按日期排序？

Question

I could use some help breaking down this puzzle.

1) I want to fetch objects from 3 entities ('A','B','C') in Core-Data (they all have different data types, except 'date') - have them in one big fetch, somehow? Should they have relations to a new entity 'D' or?

2) Later, I want to sort the big fetch by date (but I dont think it's an issue for me if I have the whole fetch).

So if any can help me pointing out 1), I would really appreciate it.

Answer 1

Here is a simple approach, easy to verify and - if needed - debug:

1. Do 3 distinct fetches, one from each entity.
2. Add the results to an array.
3. Sort the array by date.