行。这个让我好斗。
CoreData图表与您在下面看到的代码相匹配。
我想通过继承的UUID过滤实体。我正在使用以下代码创建谓词和获取请求:
NSString *aUUID = [anObjectDescription objectForKey:@"UUID"];
NSEntityDescription *entity = [NSEntityDescription entityForName:className
inManagedObjectContext:theContext];
//see if the entity already exists
NSFetchRequest *request = [[NSFetchRequest alloc] init];
[request setEntity:entity];
NSLog(@"blah the uuid is %@",aUUID);
NSLog(@"Length: %d String:[%@]", [aUUID length], aUUID);
NSPredicate *fetchPredicate = [NSPredicate predicateWithFormat:@"uuid LIKE %@",aUUID];
//NSPredicate *fetchPredicate = [NSPredicate predicateWithFormat:@"nonExisting==7"];
NSLog(@"predicate is: %@",fetchPredicate);
[request setPredicate:fetchPredicate];
NSError *aFetchError = nil;
NSMutableArray *foundEntities = [[theContext executeFetchRequest:request error:&aFetchError] mutableCopy];
//if the entity already exists then ignore the create message.
NSLog(@"found %u entities error: %@",[foundEntities count],aFetchError);
if ([foundEntities count] == 0) {
//create
NSLog(@"!!!!!!!!!!!!!!!!!!!!!!creating!!!!!!!!!!!!!!!!");
NSManagedObject *anObject = [NSEntityDescription insertNewObjectForEntityForName:className
inManagedObjectContext:theContext];
Trackable *asTrackable = (Trackable*)anObject;
asTrackable.isRemoteData = [NSNumber numberWithBool: YES];
returnEntity = anObject;
}
else{
NSLog(@"!!!!!!!!!!!!!!!!!!!!!!found!!!!!!!!!!!!!!!!");
returnEntity = [foundEntities objectAtIndex:0];
}
无论使用什么字符串创建谓词,我都会获得表中的所有值。是的,我尝试过“UUID LIKE%@”,“UUID MATCHES%@”,“UUID ==%@”以及大量变体。所有这些都以同样的方式工作。没有过滤。
以上是您在上面看到的代码输出。我尝试过的其他更改对于您在此处看到的结果没有任何区别,除了谓词字符串的日志。应该没有匹配的结果。我已经三次检查了这里请求的实体不在数据库中。它是干净的,除了一个具有不同UUID的实体。
2011-08-19 20:05:56.446 QC DBSync Example[28059:b603] working with a GameResult
2011-08-19 20:05:56.447 QC DBSync Example[28059:b603] blah the uuid is 1390FCDF-AFD1-4828-8CCC-0EBEBB741111
2011-08-19 20:05:56.447 QC DBSync Example[28059:b603] Length: 36 String:[1390FCDF-AFD1-4828-8CCC-0EBEBB741111]
2011-08-19 20:05:56.448 QC DBSync Example[28059:b603] predicate is: uuid LIKE "1390FCDF-AFD1-4828-8CCC-0EBEBB741111"
2011-08-19 20:05:56.449 QC DBSync Example[28059:b603] found 1 entities error: (null)
2011-08-19 20:05:56.449 QC DBSync Example[28059:b603] !!!!!!!!!!!!!!!!!!!!!!found!!!!!!!!!!!!!!!!
任何想法都将不胜感激。我被困了几个小时。
消息由yenrab于8/19/11在下午6:39编辑
答案 0 :(得分:0)
利
我总是在-predicateWithFormat中使用self.uuid或%K:如:
p = [NSPredicate predicateWithFormat:@“%K ==%@”,@“uuid”,aUUID];
或
p = [NSPredicate predicateWithFormat:@“self.uuid ==%@”,aUUID];
享受, 安德鲁