当我向核心数据模型添加新属性时,我想让我的应用程序能够进行自动轻量级迁移.
在Apple的指南中,这是我能找到的主题的唯一信息:
自动轻量级迁移
要请求自动轻量级迁移,请在addPersistentStoreWithType中传递的选项字典中设置适当的标志:configuration:URL:options:error:.您需要将与NSMigratePersistentStoresAutomaticallyOption和NSInferMappingModelAutomaticallyOption键对应的值设置为YES:
NSError *error;
NSURL *storeURL = <#The URL of a persistent store#>;
NSPersistentStoreCoordinator *psc = <#The coordinator#>;
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
if (![psc addPersistentStoreWithType:<#Store type#>
configuration:<#Configuration or nil#> URL:storeURL
options:options error:&error]) {
// Handle the error.
}
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我NSPersistentStoreCoordinator以这种方式初始化:
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
return persistentStoreCoordinator;
}
NSURL *storeUrl = [NSURL fileURLWithPath: [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"FC.sqlite"]];
NSError *error = nil;
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] …Run Code Online (Sandbox Code Playgroud) 如果我已经发布的v1没有版本化的Core Data模型,我可以使用"自动轻量级迁移"吗?
如果是,是否有任何密钥更改为我需要应用的文档化步骤?