iOS CoreData NSPredicate 一次查询多个属性

iOS CoreData NSPredicate to query multiple properties at once

提问by OscarTheGrouch

I am trying to use a UISearchBarto query multiple properties of a NSManagedObjectI have a NSManagedObjectcalled Person, every person has a nameand socialSecurityproperty. Right now my code can perform a search (fetch) for one of those properties or the other, but not both at the same time.

我正在尝试使用 aUISearchBar来查询NSManagedObject我有一个NSManagedObject被调用的多个属性Person，每个人都有一个name和socialSecurity属性。现在，我的代码可以对这些属性之一执行搜索（获取），但不能同时对这两个属性执行搜索（获取）。

- (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];
}

I don't know how to put both properties into this statement...

我不知道如何将这两个属性放入此语句中...

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

Any help or ideas would be greatly appreciated.

任何帮助或想法将不胜感激。

回答by Matthias Bauch

You could use a NSCompoundPredicate.

你可以使用一个NSCompoundPredicate.

Like this:

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;

there is a NSCompoundPredicatefor ANDtoo: andPredicateWithSubpredicates:

有一NSCompoundPredicate对AND过：andPredicateWithSubpredicates:

回答by CaptainRedmuff

You can append multiple search terms in an NSPredicateusing the usual boolean operands such as AND/OR.

您可以NSPredicate使用通常的布尔操作数（例如 AND/OR）在 an 中附加多个搜索词。

Something like this should do the trick.

像这样的事情应该可以解决问题。

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

Hope that helps :)

希望有帮助:)

回答by Onur Var

Addition to @Matthias's answer, you can also use NSCompoundPredicate for your AND operations like this.

除了@Matthias 的回答之外，您还可以将 NSCompoundPredicate 用于这样的 AND 操作。

Obj-C - AND

Obj-C - 与

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

Swift - AND

斯威夫特 - 和

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

Swift 3 - AND

斯威夫特 3 - 和

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

回答by Vincent

Complete solution for Swift2

Swift2 的完整解决方案

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])

回答by MFarmer

To avoid the warning Incompatible pointer types initializing 'NSCompoundPredicate *_strong' with an expression of type 'NSPredicate *', replace the following:

为避免使用类型为 'NSPredicate *' 的表达式初始化 'NSCompoundPredicate *_strong'的警告不兼容的指针类型，请替换以下内容：

NSCompoundPredicate * predicate = [NSCompoundPredicate orPredicateWithSubPredicates:subPredicates];

with this:

有了这个：

NSPredicate * predicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicates];

Source: NSCompoundPredicate

来源：NSCompoundPredicate

回答by Bean

Fraser Hess over at CISMGF.com has a great search example. You can read the post at http://www.cimgf.com/2008/11/25/adding-itunes-style-search-to-your-core-data-application/

在 CISMGF.com 上的 Fraser Hess 有一个很好的搜索示例。您可以在http://www.cimgf.com/2008/11/25/adding-itunes-style-search-to-your-core-data-application/阅读帖子

My code based off the post is:

我基于帖子的代码是：

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];
}

回答by tiritea

This is may be useful if you want to search multiple properties for anything that matches (eg UISearchControllerDelegate):

如果您想搜索多个属性以查找匹配的任何内容（例如 UISearchControllerDelegate），这可能很有用：

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];

You could then use this, for example, to filter an array of dictionaries:

例如，您可以使用它来过滤字典数组：

NSArray *results = [bigArray filteredArrayUsingPredicate:search];

(the BEGINSWITH[cd] is no magic, just means it'll match beginnings of strings and case-insensitive. Change as needed for your match criteria.)

（ BEGINSWITH[cd] 不是魔术，只是意味着它将匹配字符串的开头并且不区分大小写。根据您的匹配条件进行更改。）

回答by Dhavaprathap

For Swift:

对于斯威夫特：

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