- [__ NSDictionaryM intValue]:无法识别的选择器发送到实例0x13f26a60

Question

我正在尝试获取核心数据库的记录,但它给了我以下错误.

错误 - [__ NSDictionaryM intValue]:无法识别的选择器发送到实例0x13f26a60

在线

NSArray *results = [moc executeFetchRequest:request error:&error];

这是获取请求的完整代码.

NSManagedObjectContext *moc = [delegate managedObjectContext];


NSPredicate *predicate =[NSPredicate predicateWithFormat:@"NOT (serverId IN %@)", a];
[request setEntity:[NSEntityDescription entityForName:@"Categories" inManagedObjectContext:moc]];
[request setPredicate:predicate];

NSError *error = nil;
id results = [moc executeFetchRequest:request error:&error];
NSLog(@"results %@",results);
// error handling code
[request release];

Answer 1

我假设你的数组a不包含数字,但是字典,例如:

NSArray *a = @[
                  @{@"serverId" : @"2", ...},
                  @{@"serverId" : @"4", ...}
              ];

因为那会导致你得到的错误信息.

您必须创建一个仅包含"serverId"数字的数组,并在谓词中使用它:

NSArray *serverIds = [a valueForKey:@"serverId"];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"NOT (serverId IN %@)", serverIds];