爲什麼只有第一張唱片被添加到CD商店？

Question

我創建了一個TAB分隔文件，用於備份目的;下面的代碼用於恢復文件。該文件有5個記錄;第一個記錄包含標籤標題，其餘爲數據。

進行還原時，只有第一個記錄被還原，其他3個被標記爲不成功。這裏是恢復代碼：

- (IBAction)aRestoreCoreData:(UIButton *)sender { // user has to move file to iTunes so we can get it and restore store 

NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 

// read the file back into databuffer... 
NSFileHandle *readFile = [NSFileHandle fileHandleForReadingAtPath:[documentsPath stringByAppendingPathComponent: @"Backup.zip"]]; 
NSData *databuffer = [readFile readDataToEndOfFile]; 
[readFile closeFile]; 

// decompress the file 
NSData *uncompressedData = [databuffer gunzippedData]; 

[Books MR_truncateAll]; // truncate books entity 

Books *bks = [Books MR_createEntity]; // create entity 

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; 

// convert NSData to NSString (one big string!) contains the header row! 
NSString *inputString = [[NSString alloc] initWithData:uncompressedData encoding:NSUTF8StringEncoding]; 
NSArray *inputStringArray = [inputString componentsSeparatedByString:@"\n"]; 

// put each row's columns in in Books elements 
for(int i = 1; i < inputStringArray.count-1; i++) { 

    NSArray *inputFields = [inputStringArray[i] componentsSeparatedByString:@"\t"]; // contains data fields for each book 

    // fill record fields from strings in array 
    bks.author = inputFields[0]; 
    bks.binding = inputFields[1]; 
    bks.bookCondition = inputFields[2]; 
    bks.bookDescription = inputFields[3]; 
    bks.bookNotes = inputFields[4]; 
    bks.bookSize = inputFields[5]; 
    bks.cost = [NSDecimalNumber decimalNumberWithString:inputFields[6]]; 
    bks.dateAdded = [dateFormatter dateFromString:inputFields[7]]; 
    bks.dateUpdated = [dateFormatter dateFromString:inputFields[8]]; 
    bks.quarterUpdated = inputFields[9]; 
    bks.yearUpdated = inputFields[10]; 
    bks.doNotRepriceFlag = inputFields[11]; 
    bks.edition = inputFields[12]; 
    bks.illustrator = inputFields[13]; 
    bks.imageFilename = inputFields[14]; 
    bks.invoiceNbr = inputFields[15]; 
    bks.isbn = inputFields[16]; 
    bks.jacket = inputFields[17]; 
    bks.keywords = inputFields[18]; 
    bks.shelf = inputFields[19]; 
    bks.numberOfCopies = [NSNumber numberWithInt:[inputFields[20] intValue]]; 
    bks.pages = [NSNumber numberWithInt:[inputFields[21] intValue]]; 
    bks.price = [NSDecimalNumber decimalNumberWithString:inputFields[22]]; 
    bks.primaryCatalog = inputFields[23]; 
    bks.printing = inputFields[24]; 
    bks.privateNotes = inputFields[25]; 
    bks.pubLocation = inputFields[26]; 
    bks.pubName = inputFields[27]; 
    bks.pubYear = inputFields[28]; 
    bks.quantity = [NSNumber numberWithInt:[inputFields[29] intValue]]; 
    bks.secondaryCatalog = inputFields[30]; 
    bks.shippingDomStd = (BOOL)inputFields[31]; 
    bks.shippingDomExp = (BOOL)inputFields[32]; 
    bks.shipping1DayDom = (BOOL)inputFields[33]; 
    bks.shipping2DayDom = (BOOL)inputFields[34]; 
    bks.shippingIntlStd = (BOOL)inputFields[35]; 
    bks.shippingIntlExp = (BOOL)inputFields[36]; 
    bks.signedBy = inputFields[37]; 
    bks.sku = inputFields[38]; 
    bks.status = inputFields[39]; 
    bks.title = inputFields[40]; 
    bks.tranCode = inputFields[41]; 
    bks.volume = inputFields[42]; 
    bks.weight = [NSNumber numberWithInt:[inputFields[43] intValue]]; 

    [defaultContext MR_saveToPersistentStoreWithCompletion: ^(BOOL success, NSError *error) { 
     if (error) { 
      NSLog(@"--> Error - SKU: %@",inputFields[38]); 
     } 
     else if(success) { 
      NSLog(@"--> Added - SKU: %@",inputFields[38]); 
     } 
     else 
      NSLog(@"--> Unsuccessful - SKU: %@",inputFields[38]); 
    }]; 
} 
} 

這是從控制檯輸出：

2014-09-18 14:54:43.502 BookI[32513:60b] --> Added - SKU: 1 
2014-09-18 14:54:43.502 Book[32513:60b] --> Unsuccessful - SKU: 2 
2014-09-18 14:54:43.502 Book[32513:60b] --> Unsuccessful - SKU: 3 
2014-09-18 14:54:43.502 Book[32513:60b] --> Unsuccessful - SKU: 4 

我在做什麼錯？

Answer 1

Spokane-Dude， 我想你想在你的循環中創建一個新的實體，而不是重複使用同一個實體並覆蓋屬性和保存。

一旦保存了第一個Book實體，就不會爲後續記錄創建任何其他新實體。