CoreData countForFetchRequest说'实体未找到' [英] CoreData countForFetchRequest says 'entity not found'

问题描述

当尝试计算受管理对象上下文中的实体时，遇到一个奇怪的问题。

I'm experiencing a strange problem when trying to count the entities in a managed object context.

- (NSUInteger)countEntity:(NSString *)entityName 
                inContext:(NSManagedObjectContext *)context{

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:entityName                     
                                                  inManagedObjectContext:context];
    [request setEntity:entity];
    [request setIncludesSubentities:NO];
    NSError *error = nil;
    NSUInteger count = [context countForFetchRequest:request error:&error];
    [request release];
    return count;
}

行：

NSUInteger count = [context countForFetchRequest:request error:&error];

抛出 NSInternalInconsistencyException原因：'entity not found'

更改为：

NSUInteger count = [[context executeFetchRequest:request error:&error] count];

无任何问题。

这里的损失。任何想法？

I'm at loss here. Any ideas?

谢谢！

/ Oskar

推荐答案

今天跑到这里。当我引入第二个持久存储时开始发生。你在moc有多个商店吗？
-Ken

Running into this today. Started happening when I introduced a second persistent store. Do you have more than one store in the moc? -Ken

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