iPhone开发-使用CoreData查询相关记录
我有一个案例，我有三个具有一对多和一对多关系的实体：
Entity A (Entity B relationhip),
Entity B (Entity A relationship, Entity C relationship),
Entity C (Entity B relationhip)
我有实体 A 的引用，现在我想获取所有相关的实体 C 记录。我怎样才能做到这一点？ （用最少的代码）
编辑：这是另一种表达方式。
我们可以与 CoreData 执行连接吗？例如，（这是一个非常粗略的例子），我们有一个以下实体关系：
Grand Parent (1)---(m) Parent
Parent (1)---(m) Child
那么，现在如果我有“阿尔伯特”祖父母，并且我想得到他所有的孙子，我该怎么做？
I have a case where i have three entities with one-to-many and one-to-many relationships:
Entity A (Entity B relationhip),
Entity B (Entity A relationship, Entity C relationship),
Entity C (Entity B relationhip)
I have the reference of Entity A, and now i want to fetch all the related Entity C records. How can i do that? (with least amount of code)
Edit: Here's another way to put it.
Can we perform joins with CoreData. For example, (and this is a very crude example), We have a following entity-relationship:
Grand Parent (1)---(m) Parent
Parent (1)---(m) Child
So, now if i have "Albert" the Grand Parent, and i want to get all his grand children, how can i do that?
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如果其他人偶然发现类似的情况，这对我有用：
我主要感兴趣的是读取实体 C 中单个字段的数据（链接到 myEntityA 对象）。这里的关键概念是“不要将 CoreData 视为‘数据库’”。
In case someone else stumble across a similar situation, here's what worked for me:
I was mainly interesting in reading the data of a single field in Entity C (that's linked to myEntityA object). The key concept here is that "don't think of CoreData as a 'database'".