Coredata chained Relationship

Question

What is the best way to update or add data if relationships are chained.

I have my coredata designed like this:

I have 3 Entities

1) User To_Many Category

2) Category To_Many Item

3) Item To_One Category

User is required before adding a Category, and Category is required before adding an Item

Answer 1

简单。只需设置一对一关系，相应的反向关系将由Core Data自动设置。

newItem.category = category
category.user = user

根据最佳做法，我将笨拙的属性名称itemCategory，categoryUser，categoryInUser重命名为category，user，{分别为{1}}。