使用NSPredicate获取核心数据对象的问题

在开始之前，让我告诉你我的数据模型是什么样的：

然后我有一个带有以下谓词的获取请求：

NSArray *allowedPackNames = @[@"success, happiness, free"]; self.fetchedResultsController = [Author MR_fetchAllGroupedBy:nil withPredicate:[NSPredicate predicateWithFormat:@"ANY quotes.quote.pack.packName IN %@", allowedPackNames] sortedBy:AuthorKeys.name ascending:YES delegate:self]; 

我想获取所有具有成功或幸福或免费的packName引用的作者。 如下面的关系表中所示，作者有一组NSB引号。 但是，当我执行此操作时，我收到以下错误：

 CoreData: error: (1) I/O error for database at /Users/Abdul/Library/Application Support/iPhone Simulator/6.1/Applications/DA17421B-A54D-42E3-9694-FDCBFF7F8BA4/Library/Application Support/MyCoolApp/MyCoolApp.sqlite. SQLite error code:1, 'no such column: t2.ZQUOTE' 2013-04-05 15:26:47.175 MyCoolApp[78622:c07] Core Data: annotation: -executeRequest: encountered exception = I/O error for database at /Users/Aditya/Library/Application Support/iPhone Simulator/6.1/Applications/DA17421B-A54D-42E3-9694-FDCBFF7F8BA4/Library/Application Support/MyCoolApp/MyCoolApp.sqlite. SQLite error code:1, 'no such column: t2.ZQUOTE' with userInfo = { NSFilePath = "/Users/Abdul/Library/Application Support/iPhone Simulator/6.1/Applications/DA17421B-A54D-42E3-9694-FDCBFF7F8BA4/Library/Application Support/MyCoolApp/MyCoolApp.sqlite"; NSSQLiteErrorDomain = 1; } 

知道为什么吗？

Answer 1

如果我看得正确，谓词应该是

 [NSPredicate predicateWithFormat:@"ANY quotes.pack.packName IN %@", allowedPackNames] 

即你必须删除“引用”，这是引用实体的属性，而不是关系。