默认情况下，iPhone中的核心数据使用哪个持久存储 [英] Which persistent store is used by default in core data in iPhone

问题描述

我在我的应用程序中创建多个持久存储，但我只使用一个持久存储协调器和管理对象模型。现在我的问题是当我调用保存方法在托管对象上下文，其持久存储它将用于保存对象。所以我想指定用于保存对象的持久存储。从数据库中获取对象时，我想确保我的读取查询应该在特定的存储上执行，以便只从该存储中获取对象。任何帮助？

I am creating multiple persistent store in my application, but I am using only one persistent store coordinator and managed object model. Now my question is when I call save method on managed object context, which persistent store it will use to save the object. So I want to specify the persistent store to be used to save the object. Same while fetching the objects from database, I want to ensure that my fetch query should be executed on a particular store so that I get objects from that store only. Any help?

推荐答案

获取不应该是一个问题。可以修改抓取请求，以使用NSFetchRequest上的setAffectedStores：方法搜索特定商店。

Fetching should not be an issue. The fetch request can be modified to search particular stores using the setAffectedStores: method on an NSFetchRequest.

创建对象时，可以将实体分配给特定使用NSManagedObjectContext上的assignObject：toPersisentStore：方法存储。

When you're creating an object, you can assign the entity to a particular store using the assignObject:toPersisentStore: method on NSManagedObjectContext.

对于你的问题，我没有真正的一个默认机制，我知道，您只需要将受影响的商店设置为所有商店：

As to your question, there isn't really a default mechanism that I am aware of, and it may be that you simply need to set the affected stores to all of your stores:

[request setAffectedStores：[NSArray arrayWithObjects：firstStore，secondStore，thirdStore，nil ]];

确保您查找所有正确的地点。

To be sure that you're looking in all the right places.

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