ios - 如何查询核心数据中按唯一值分组的值？

Question

考虑上述具有一对多关系的模型。

假设我正在查询以获取患者名字或姓氏为“xyz”(有多个“xyz”记录)的托管对象。

如何获得唯一的“xyz”作为字典对象，并将重复的“xyz”托管对象作为该字典中的对象。

到目前为止，我能够获得不同的值，而且我能够获得托管对象数组，其中“xyz”是谓词字符串。

但我无法想出一种方法来获取字典数组及其对象作为重复值的托管对象。

我想要一个具有唯一值的字典数组作为字典名称，字典中的对象应该是托管对象/字典。

有人可以帮我解决这个问题吗？如果有任何不明白的地方，我会提供更多的解释。

谢谢

Answer 1

#pragma mark - Search Patients By Patient Name

-(NSArray*)GetBillsForPatientwith:(NSString*)name{

NSMutableArray *AllBillsData = [[NSMutableArray alloc]init];

NSArray *_strings = [self GetSplitStrings:name];

NSManagedObjectContext *context = [CoreDataManager GetCoreDataManager].managedObjectContext;
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:_Claims inManagedObjectContext:context];
[fetchRequest setEntity:entity];

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"patient_FirstName" ascending:YES];
NSArray *sortDescriptors = @[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
NSMutableArray *subPredicates = [NSMutableArray array];


for (NSString *strings in _strings) {
    [subPredicates addObject:
     [NSPredicate predicateWithFormat:@"patient_FirstName CONTAINS[cd] %@ OR patient_LastName contains[cd] %@",strings,strings]];
}
NSCompoundPredicate *predicate_ = [[NSCompoundPredicate alloc]initWithType:NSOrPredicateType subpredicates:subPredicates];
[fetchRequest setReturnsObjectsAsFaults:NO];
[fetchRequest setPredicate:predicate_];
fetchRequest.returnsDistinctResults = YES;
fetchRequest.resultType = NSDictionaryResultType;

fetchRequest.propertiesToFetch = [NSArray arrayWithObjects:[[entity propertiesByName] objectForKey:@"patient_FirstName"],[[entity propertiesByName] objectForKey:@"patient_LastName"], nil];
//fetchRequest.propertiesToGroupBy = [NSArray arrayWithObjects:[[entity propertiesByName] objectForKey:@"patient_FirstName"],[[entity propertiesByName] objectForKey:@"patient_LastName"], nil];

NSError *error;
NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
if (fetchedObjects == nil) {
    // Handle the error.
}

for (NSDictionary *names in fetchedObjects) {
    // [AllBillsData addObject:names];
    [AllBillsData addObject:[self GetCorrespondingClaimsForNames:names]];
}
return AllBillsData;
}
//Entangled Method
-(NSArray*)GetCorrespondingClaimsForNames:(id)Names{
    NSManagedObjectContext *context = [CoreDataManager 
GetCoreDataManager].managedObjectContext;
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:_Claims inManagedObjectContext:context];
    [fetchRequest setEntity:entity];

    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"patient_FirstName" ascending:YES];
    NSArray *sortDescriptors = @[sortDescriptor];
    [fetchRequest setSortDescriptors:sortDescriptors];
    NSMutableArray *subPredicates = [NSMutableArray array];
    [subPredicates addObject:
     [NSPredicate predicateWithFormat:@"patient_FirstName ==[cd] %@ AND patient_LastName ==[cd] %@",[Names valueForKey:@"patient_FirstName"],[Names valueForKey:@"patient_LastName"]]];

    NSCompoundPredicate *predicate_ = [[NSCompoundPredicate alloc]initWithType:NSOrPredicateType subpredicates:subPredicates];
    [fetchRequest setReturnsObjectsAsFaults:NO];
    [fetchRequest setPredicate:predicate_];

    NSError *error;
    NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
    if (fetchedObjects == nil) {
        // Handle the error.
    }

    return fetchedObjects;

}