如何使用MagicalRecord设置Core Data轻量级迁移？ [英] How do I set up Core Data lightweight migration using MagicalRecord?

问题描述

我打了一个砖墙，试图使用MagicalRecord设置轻量级的Core Data迁移。我已经查看了关于这个问题的所有帖子，使用Google和SO。我了解 persistentStoreCoordinator 的工作方式以及我想要进行的设置。

I have hit a brick wall trying to setup lightweight migration of Core Data using MagicalRecord. I have looked at all of the posts on this subject, using Google and SO. I understand how the persistentStoreCoordinator works and what the settings I am trying to make also do.

这是我的代码：

AppDeligate.h

NSPersistentStoreCoordinator *persistentStoreCoordinator;

AppDelegate.m

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {

if (persistentStoreCoordinator != nil) {
    return persistentStoreCoordinator;
}

NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"saori.sqlite"]];

// handle db upgrade
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
                         [NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
                         [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];

NSError *error = nil;
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];

if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {

    // Handle error
}

return persistentStoreCoordinator;

}

以下错误，我明白;我不知道这些对象在哪里（我已经在我的应用程序，看不到任何东西）：

I'm getting the following errors, which I understand; what I don't know is where are these objects (I have looked in my app, and found nothing):

没有可见@interface 'AppDelegate'声明选择器'applicationDocumentsDirectory'和

No visible @interface for 'AppDelegate' declares the selector 'applicationDocumentsDirectory' and

没有可见@interface for'AppDelegate'声明选择器'managedObjectModel'

No visible @interface for 'AppDelegate' declares the selector 'managedObjectModel'

我已经创建了商店：

大多数，如果不是所有的代码我看过是类似的;我不知道MagicalRecord是否为我处理这个，因为我找不到任何文档，指示如何使用MR。我的问题是：我需要做什么来使这项工作？

Most, if not all of the code I have looked at is similar; I don't know if MagicalRecord handles this for me or not because I can't find any docs that would indicate how to do this using MR. My question is: what do I have to do to make this work?

推荐答案

MagicalRecord的要点是， for：

The whole point of MagicalRecord is that this is managed for you:

[MagicalRecord setupCoreDataStackWithAutoMigratingSqliteStoreNamed:####];

检查有关Core Data堆栈设置的文档这里。

Check the docs about the Core Data stack setup here.

这篇关于如何使用MagicalRecord设置Core Data轻量级迁移？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！