核心数据错误

Question

当我在我的实体上添加autoLogin属性Utente的代码不工作，如果我删除此属性的代码工作，为什么？ PS：我需要新的属性，有人可以帮我请:)

 
Unresolved error Error Domain=NSCocoaErrorDomain Code=134100 "The operation couldn’t be completed. (Cocoa error 134100.)" UserInfo=0x10970aae0 {metadata={ 
    NSPersistenceFrameworkVersion = 479; 
    NSStoreModelVersionHashes =  { 
     Utente = ; 
    }; 
    NSStoreModelVersionHashesVersion = 3; 
    NSStoreModelVersionIdentifiers =  (
     "" 
    ); 
    NSStoreType = SQLite; 
    NSStoreUUID = "C879290E-F81B-4D22-B6FF-12F34B97820F"; 
    "_NSAutoVacuumLevel" = 2; 
}, reason=The model used to open the store is incompatible with the one used to create the store}, { 
    metadata =  { 
     NSPersistenceFrameworkVersion = 479; 
     NSStoreModelVersionHashes =   { 
      Utente = ; 
     }; 
     NSStoreModelVersionHashesVersion = 3; 
     NSStoreModelVersionIdentifiers =   (
      "" 
     ); 
     NSStoreType = SQLite; 
     NSStoreUUID = "C879290E-F81B-4D22-B6FF-12F34B97820F"; 
     "_NSAutoVacuumLevel" = 2; 
    }; 
    reason = "The model used to open the store is incompatible with the one used to create the store"; 
} 

代码：

//caricamento DB 
AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; 
NSManagedObjectContext *context = [appDelegate managedObjectContext]; //the error signal is here 
NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Utente" inManagedObjectContext:context]; 
NSFetchRequest *request = [[NSFetchRequest alloc] init]; 
[request setEntity:entityDesc]; 



NSManagedObject *matches = nil; 

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

if ([objects count] == 0) 
{ 
    NSLog(@"No Email save"); 
} 
else 
{ 
    for (int i = 0; i < [objects count]; i++) 
    { 
     matches = objects[i]; 
     //NSManagedObject *o = objects[i]; 
     //[context deleteObject:o]; //cancella 
     //[context save:&error]; 

     //email 
     NSLog(@"email salvata : %@",[matches valueForKey:@"email"]); 
     emailText.text=[matches valueForKey:@"email"]; 


     //password 
     NSString * psw =[matches valueForKey:@"password"]; 
     if (psw) 
     { 
      NSLog(@"password salvata : %@",[matches valueForKey:@"password"]); 
      passwordText.text=[matches valueForKey:@"password"]; 

      //auto-login 
      NSString * psw =[matches valueForKey:@"autoLogin"]; 
      if (psw) 
      { 
       [self login:self]; 
      } 
     } 

Answer 1

事实上，一旦你部署它集成了核心数据的应用程序，生成的模型被版本。

如果您需要为您的实体添加新属性，那么您需要通过选择菜单“编辑器 - >添加模型版本”创建新版本的CoreData模型，然后对您的实体进行更改。

如果你的修改是简单的（列删除，列相加......），CoreData可以处理没有太大的特定代码的轻量级迁移，但是你需要在你的项目中的CoreData的所有版本模型，以使iOS能够为现有商店执行迁移。

所有在苹果的文档，它可以在这里找到充分详细：https://developer.apple.com/library/ios/documentation/cocoa/Conceptual/CoreDataVersioning/Articles/Introduction.html