的iOS CoreData NSPredicate来一次

问题描述：

我试图用一个UISearchBar查询的NSManagedObject 多个属性查询多个属性我有一个名为PersonNSManagedObject，每个人都有一个name和socialSecurity财产。现在我的代码可以为其中一个属性或其他属性执行搜索（提取），但不能同时执行这两个属性。的iOS CoreData NSPredicate来一次

- (void) performFetch 
{  
    [NSFetchedResultsController deleteCacheWithName:@"Master"]; 

    // Init a fetch request 
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; 
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"MainObject" inManagedObjectContext:self.managedObjectContext]; 
    [fetchRequest setEntity:entity]; 

    // Apply an ascending sort for the color items 
    //NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"Term" ascending:YES selector:nil]; 
    NSSortDescriptor *sortDescriptor; 
    sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"fullName" ascending:YES selector:@selector(caseInsensitiveCompare:)];  

    NSArray *descriptors = [NSArray arrayWithObject:sortDescriptor]; 
    [fetchRequest setSortDescriptors:descriptors]; 

    // Recover query 
    NSString *query = self.searchDisplayController.searchBar.text; 
    //if (query && query.length) fetchRequest.predicate = [NSPredicate predicateWithFormat:@"Term contains[cd] %@", query]; 
    if(searchValue==1) 
    { 
     if (query && query.length) fetchRequest.predicate = [NSPredicate predicateWithFormat:@"name contains[cd] %@", query]; 
    } 
    else { 
     if (query && query.length) fetchRequest.predicate = [NSPredicate predicateWithFormat:@"socialSecurity contains[cd] %@", query]; 
    }   

    // Init the fetched results controller 
    NSError *error; 
    self.fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:@"pLLetter" cacheName:nil]; 

    self.fetchedResultsController.delegate = self; 

    if (![[self fetchedResultsController] performFetch:&error]) NSLog(@"Error: %@", [error localizedDescription]); 

    [self.tableView reloadData]; 
}

我不知道如何把两个属性到本声明

if (query && query.length) fetchRequest.predicate = [NSPredicate predicateWithFormat:@"name contains[cd] %@", query];

任何帮助或想法，将不胜感激。

答

可以使用通常的布尔操作数，如AND/OR追加在NSPredicate多个搜索词。

像这样的东西应该做的伎俩。

[NSPredicate predicateWithFormat:@"name contains[cd] %@ OR ssid contains[cd] %@", query, query];

希望帮助:)

if（query && query.length）fetchRequest.predicate = [NSPredicate predicateWithFormat：@“（fullName contains [cd]％@）||（socialSecurity contains [cd]％@） “，查询，查询]; – OscarTheGrouch

答

你可以使用一个NSCompoundPredicate。

像这样：

NSPredicate *predicateName = [NSPredicate predicateWithFormat:@"name contains[cd] %@", query]; 
NSPredicate *predicateSSID = [NSPredicate predicateWithFormat:@"socialSecurity contains[cd] %@", query]; 
NSArray *subPredicates = [NSArray arrayWithObjects:predicateName, predicateSSID, nil]; 

NSPredicate *orPredicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates]; 

request.predicate = orPredicate;

存在用于AND太一个NSCompoundPredicate：andPredicateWithSubpredicates:

+1使用NSCompoundPredicate。 – CaptainRedmuff

NSArray * subPredicates = @ [predicateName，predicateSSID];我喜欢Objective C 2.0 NSArray语法，只是说 –

答

为了避免该警告不相容指针类型初始化 'NSCompoundPredicate * _strong' 与类型的表达式 'NSPredicate *'替换如下：

NSCompoundPredicate * predicate = [NSCompoundPredicate orPredicateWithSubPredicates:subPredicates];

本：

NSPredicate * predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];

来源：NSCompoundPredicate

答

弗雷泽在赫斯在CISMGF.com有一个伟大的搜索例子。您可以根据关闭后阅读http://www.cimgf.com/2008/11/25/adding-itunes-style-search-to-your-core-data-application/

我的代码的帖子是：

NSArray *searchTerms = [searchText componentsSeparatedByString:@" "]; 
if ([searchTerms count] == 1) { // Search in name and description 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(name contains[cd] %@) OR (desc contains[cd] %@)", searchText, searchText]; 
    [self.searchFetchedResultsController.fetchRequest setPredicate:predicate]; 
} else { // Search in name and description for multiple words 
    NSMutableArray *subPredicates = [[NSMutableArray alloc] init]; 
    for (NSString *term in searchTerms) { 
     NSPredicate *pred = [NSPredicate predicateWithFormat:@"(name contains[cd] %@) OR (desc contains[cd] %@)", term, term]; 
     [subPredicates addObject:pred]; 
    } 
    NSPredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:subPredicates]; 
    [self.searchFetchedResultsController.fetchRequest setPredicate:predicate]; 
}

答

对于斯威夫特：

var predicate = NSCompoundPredicate(
     type: .AndPredicateType, 
     subpredicates: [predicate1, predicate2] 
    )

答

为Swift2

let request = NSFetchRequest(entityName: "Location") 
let subPredicate1 = NSPredicate(format: "(name = %@)", searchString) 
let subPredicate2 = NSPredicate(format: "(street = %@)", searchString) 
let subPredicate3 = NSPredicate(format: "(city = %@)", searchString) 

request.predicate = NSCompoundPredicate(type: .OrPredicateType, subpredicates: [subPredicate1, subPredicate2, subPredicate3])

答

加成@完整的解决方案Matthias的回答是，你也可以使用NSCompoundPredicate来处理你的AND操作。

的OBJ-C - AND

NSPredicate *predicate1 = [NSPredicate predicateWithFormat:@"X == 1"]; 
NSPredicate *predicate2 = [NSPredicate predicateWithFormat:@"X == 2"]; 
NSPredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:@[predicate1, predicate2]];

夫特 - AND

let predicate1:NSPredicate = NSPredicate(format: "X == 1") 
let predicate2:NSPredicate = NSPredicate(format: "Y == 2") 
let predicate:NSPredicate = NSCompoundPredicate(andPredicateWithSubpredicates: [predicate1,predicate2])

夫特3 - AND

let predicate1 = NSPredicate(format: "X == 1") 
    let predicate2 = NSPredicate(format: "Y == 2") 
    let predicateCompound = NSCompoundPredicate(type: .and, subpredicates: [predicate1,predicate2])

答

这可以是使用FUL如果您要搜索多个属性的任何匹配（如UISearchControllerDelegate）：

NSString *searchFor = @"foo"; 
NSArray *fields = @[@"Surname", @"FirstName", @"AKA", @"Nickname"]; // OR'd dictionary fields to search 
NSMutableArray *predicates = NSMutableArray.new; 
for (NSString *field in fields) { 
    [predicates addObject:[NSPredicate predicateWithFormat:@"(%K BEGINSWITH[cd] %@)", field, searchFor]]; 
} 
NSPredicate *search = [NSCompoundPredicate orPredicateWithSubpredicates:predicates];

然后，您可以使用此功能，例如，过滤词典的数组：

NSArray *results = [bigArray filteredArrayUsingPredicate:search];

（该BEGINSWITH [cd]不是魔术，只是意味着它会匹配字符串的开始和不区分大小写。）

的iOS CoreData NSPredicate来一次

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