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我正在尝试使用谓词来获取我想要搜索的数据所在的数据 NSSet

@property (nonatomic, retain) NSSet *categories;
@property (nonatomic, retain) NSString *otherDetails;
@property (nonatomic, retain) NSNumber *id;

该NSSet类别是从另一个实体组成,包含:

@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSNumber *id;

然后尝试通过谓词得到这个

NSFetchRequest *fetcher =[NSFetchRequest fetchRequestWithEntityName:@"MyEntity"];
fetcher.predicate = [NSPredicate predicateWithFormat:@categories in  %@", catList];

其中catList是:

NSmutableArray *catList = [[NSMutableArray alloc] init];

并填充数据

这就是给我以下错误

'NSInvalidArgumetException', reason: 'unimplemented SQL generation for predicate: (categories IN {"this", "that"});

我尝试将其更改为使用这样的NSSet字段

fetcher.predicate = [NSPredicate predicateWithFormat:@categories.name in  %@", catList];

但这没用.

如果我更改谓词使用NSString它不会出错,但由于数据不同,不会返回任何结果.

fetcher.predicate = [NSPredicate predicateWithFormat:@categories …