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我的 iPad 应用程序中的功能需要我偶尔清除整个 coredata 数据库。我这样做如下：

+(BOOL)clearEntireDB
{
    // Empty all collections

    NSArray* stores = [NSArray arrayWithObjects:@"ServerToken",@"Client",@"User",@"Form",@"Company",@"Contact",@"Response",@"Image",@"Thumbnail",@"SearchIndex",@"Tag",@"Literature", nil];

    BOOL rc=YES;
    for (int i=0;i<stores.count;i++)
    {
        if (rc==YES)
        {
            NSString* storeName = (NSString*)[stores objectAtIndex:i];
            rc=[HPSDbUtilities clearStore:storeName];
        }
    }

    if (rc==YES)
    {
    // Now need to delete all files in the document folder
        rc = [HPSFileHelper removeAllDocumentFiles];
    }


    return rc;
}
+(BOOL)clearStore:(NSString*)storeName
{
    BOOL rc=NO;

    @try{

        NSLog(@"HPSDbUtilities::clearStore %@",storeName);

        HPSAppDelegate* appDelegate = [[UIApplication sharedApplication] delegate];
        NSManagedObjectContext * context = appDelegate.managedObjectContext;
        NSFetchRequest * fetch = [[NSFetchRequest alloc] init];
        [fetch setEntity:[NSEntityDescription entityForName:storeName inManagedObjectContext:context]];
        NSArray * result = [context executeFetchRequest:fetch error:nil];
        for (id record in result)
            [context deleteObject:record];

        NSError* error;

        if ([context save:&error] == YES)
        {
            NSLog(@"HPSDbUtilities::clearStore SAVED"); 
        }else {
            NSLog(@"HPSDbUtilities::clearStore NOT saved"); 
        }
        rc=YES;

    }@catch (NSException * e) {

        NSLog(@"clearStore Exception: %@", e);
        rc=NO;
    }

    return rc;
}

该应用程序有一个辅助线程，它使核心数据数据库与网络保持同步。清除整个数据库时，我停止了这个辅助线程。清除数据库后，我再次启动辅助线程。

在我清除数据库之前，辅助线程中的所有处理都可以正常工作。然后辅助线程保存处理开始失败，并出现以下错误：

Error Domain=NSCocoaErrorDomain Code=134030 "The operation couldn’t be completed. (Cocoa error 134030.)" UserInfo=0x261c10 {NSAffectedStoresErrorKey=(
    "<NSSQLCore: 0xfe91310> (URL: file://localhost/var/mobile/Applications/3013185E-8171-4A1F-9E1F-6A02E7664510/Documents/Model.sqlite)"
), NSUnderlyingError=0x261b90 "The operation couldn’t be completed. (Cocoa error 4.)", NSFilePath=/var/mobile/Applications/3013185E-8171-4A1F-9E1F-6A02E7664510/Documents/Model.sqlite}

辅助线程代码分布在多个类中，因此我无法在此处真正展示所有内容，但它很简单，只需创建 MOC、更新记录并保存 MOC。

任何人都可以阐明这个问题吗？

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