ios - 在 CoreData 中过滤？

Question

我写了一个方法如下

-(NSArray*)getClubDetailedDeals:(NSString *)clubID{

    NSError *error;
    NSManagedObjectContext *context = [self managedObjectContext];

    NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init];

    NSEntityDescription *entity = [NSEntityDescription entityForName:@"ClubDetailsDeals"
                                              inManagedObjectContext:context];

    [fetchRequest setEntity:entity];

    NSArray *fetchedArray1 = [[context executeFetchRequest:fetchRequest error:&error] mutableCopy];

    ClubDetailsDealsDAO *obb = [fetchedArray1 objectAtIndex:0];

    NSLog(@"MY ID IS %@ and count is %d", obb.dealname, [fetchedArray1 count]);




    NSLog(@"deal is %@", clubID);

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(%K CONTAINS %@)", @"clubid", clubID];

    //NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dealid contains[cd] %@", dealID];

    [fetchRequest setPredicate:predicate];

    NSArray *fetchedArray = [[context executeFetchRequest:fetchRequest error:&error] mutableCopy];

    NSLog(@"COUNT of arary is ~~~~ %d", [fetchedArray count]);

    return fetchedArray;
}

这里，这个LOG中的Array个数是

* NSLog(@"MY ID IS %@ and count is %d", obb.dealname, [fetchedArray1 count]);*

显示不止一个元素，随着我添加的更多，它会适当增加。

但是当我使用这个查询来获取它时

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(%K CONTAINS %@)", @"clubid", clubID];

它什么也不返回，即使是 OBJECT 在 CoreData 中也可用。

那么通过匹配俱乐部ID（即NSString）获取的正确查询是什么？

Answer 1

尝试这个，

-(NSArray*)getClubDetailedDeals:(NSString *)clubID{

    NSError *error;
    NSManagedObjectContext *context = [self managedObjectContext];

    NSFetchRequest * fetchRequest = [[NSFetchRequest alloc] init];

    NSEntityDescription *entity = [NSEntityDescription entityForName:@"ClubDetailsDeals"
                                              inManagedObjectContext:context];

    [fetchRequest setEntity:entity];

[fetchRequest setPredicate:[NSPredicate predicateWithFormat:@"(dealid
 contains[cd] %@)", clubID]];

    NSArray *fetchedArray = [[context executeFetchRequest:fetchRequest error:&error] mutableCopy];

    NSLog(@"COUNT of arary is ~~~~ %d", [fetchedArray count]);

    return fetchedArray;
}