獲取超過1000時，核心數據碰撞對象

Question

當我試圖從核心數據獲取超過1000個NSManagedObjects，我的應用程序崩潰與此消息：

error: (1) I/O error for database at .../Documents/Stores/Model.sqlite. 
SQLite error code:1, 'Expression tree is too large (maximum depth 1000)' 
CoreData: error: (1) I/O error for database at .../Documents/Stores/Model.sqlite. 
SQLite error code:1, 'Expression tree is too large (maximum depth 1000)' 

我用它來獲取由用戶選擇的對象的代碼是這樣的：

NSManagedObjectContext *context = cdh.context; 
NSFetchRequest *request = [[NSFetchRequest alloc] init]; 
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Spot" inManagedObjectContext:context]; 
NSError *error = nil; 
[request setEntity:entity]; 
request.includesPropertyValues = NO; 

NSMutableArray *subPredicatesArray = [NSMutableArray array]; 

for (NSString *string in uuidStrings) 
{ 
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"%K like %@", @"sID", string]; 
    [subPredicatesArray addObject:predicate]; 
} 

NSCompoundPredicate *compoundPredicate = [NSCompoundPredicate orPredicateWithSubpredicates:subPredicatesArray]; 
[request setPredicate:compoundPredicate]; 

NSArray *fetchedObjects = [context executeFetchRequest:request error:&error]; 

有沒有更好的方式來獲取1000+對象，這將不會導致我的應用程序崩潰？

Answer 1

假設uuidStrings包含了sID屬性完全匹配項，你應該能夠用這種（未經測試），以替換代碼：

// remove subPredicatesArray, the loop and compoundPredicate 

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"sID IN %@", uuidStrings]; 
[request setPredicate:predicate];