将sqlite导入coredata

Question

我之前已经将sqlite预先填充的数据库导入到我的coredata项目中，但是现在我已经在3.2.5中创建了一个项目。 xcode，在AppDelegate中将nsurl更改为nstring，所以我同意了，但是现在我的sqlite不会导入到项目中，

如果我将PersistentStoreCoordinator留空以创建新的数据库，则可以正常工作，

 NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"ChildCare_v02.sqlite"];

但是当我更改代码以导入预填充的db时（为澄清起见，称为相同名称），它会警告我并崩溃，

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {
if (persistentStoreCoordinator_ != nil) {
return persistentStoreCoordinator_;
}
NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"ChildCare_v02.sqlite"]; //WARNING !! here
NSURL *storeUrl = [NSURL fileURLWithPath:storePath]; 
//NSURL *storeURL = [[self applicationDocumentsDirectory]    URLByAppendingPathComponent:@"ChildCare_v02.sqlite"]; //actual SDK style for blank db

// Put down default db if it doesn't already exist
    NSFileManager *fileManager = [NSFileManager defaultManager];
   if (![fileManager fileExistsAtPath:storePath]) {
    NSString *defaultStorePath = [[NSBundle mainBundle]  pathForResource:@"ChildCare_v02" ofType:@"sqlite"];
    if (defaultStorePath) {
        [fileManager copyItemAtPath:defaultStorePath toPath:storePath error:NULL];
    }
    }
NSError *error = nil;
persistentStoreCoordinator_ = [[NSPersistentStoreCoordinator alloc]  initWithManagedObjectModel:[self managedObjectModel]];
if (![persistentStoreCoordinator_ addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:nil error:&error]) {


NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
    }    
    return persistentStoreCoordinator_;
    }

这是控制台中的崩溃日志

-[NSURL stringByAppendingPathComponent:]: unrecognized selector sent to instance  0x5b40e50
 2011-02-15 21:06:59.245 Staff_02c[469:207] *** Terminating app due to uncaught  exception 'NSInvalidArgumentException', reason: '-[NSURL stringByAppendingPathComponent:]:     unrecognized selector sent to instance 0x5b40e50'

请问如何解决？ 就在我艰难的时候，我正在获取核心数据！ 面团！！

Answer 1

苹果更改了在核心数据模板中返回应用程序字典的助手方法。

您所依赖的版本：

- (NSString *)applicationDocumentsDirectory {
    return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
}

但是苹果把它改成了这个版本

- (NSURL *)applicationDocumentsDirectory {
    return [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
}

---

要修复它，只需更改此即可。

NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"ChildCare_v02.sqlite"]; //WARNING !! here
NSURL *storeUrl = [NSURL fileURLWithPath:storePath]; 
//NSURL *storeURL = [[self applicationDocumentsDirectory]    URLByAppendingPathComponent:@"ChildCare_v02.sqlite"]; //actual SDK style for blank db

对此

//NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"ChildCare_v02.sqlite"]; //WARNING !! here
//NSURL *storeUrl = [NSURL fileURLWithPath:storePath]; 
NSURL *storeUrl = [[self applicationDocumentsDirectory]    URLByAppendingPathComponent:@"ChildCare_v02.sqlite"]; //actual SDK style for blank db

抱歉，但是omfg

Answer 2

谢谢Ishu，您通过指出NSArray的方式对我有很大帮助！！！

这就是我最终获得启发的解决方案！

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {

if (persistentStoreCoordinator_ != nil) {
    return persistentStoreCoordinator_;
}



NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"ChildCare_v02.sqlite"];

NSString *storePath = [[NSBundle mainBundle] pathForResource:@"ChildCare_v02" ofType:@"sqlite"];


NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"ChildCare_v02.sqlite"]; //este es el que sirve!!! CREE ESTE

NSLog(@"store URL %@", storeURL);

    // Put down default db if it doesn't already exist
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:writableDBPath]) {
    NSLog(@"proceda aqui");
    NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"ChildCare_v02" ofType:@"sqlite"];
    NSLog(@"no existe todavia");
    NSLog(@"defalultStorePath %@", defaultStorePath);


    if (defaultStorePath) {
      [fileManager copyItemAtPath:defaultStorePath toPath:writableDBPath error:NULL];
        NSLog(@"storePath= %@", storePath);
    }
}    

NSError *error = nil;
persistentStoreCoordinator_ = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![persistentStoreCoordinator_ addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {

NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
    }    

   return persistentStoreCoordinator_;
    }

希望它对像我这样想要将预填充的sqlite导入coredata db的新手有所帮助，请注意，首先需要创建空白db，以保留结构，然后填充（我使用SQLite数据库浏览器将CSV列导入我的sqlite）

ss9

Answer 3

您根本不需要使用NSString路径，都可以使用NSURL方法来完成。

NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Database.sqlite"];

// If the database doesn't exist copy in the default one
if (![storeURL checkResourceIsReachableAndReturnError:NULL])
{
    NSURL *defaultStoreURL = [[NSBundle mainBundle] URLForResource:@"Database" withExtension:@"sqlite"];

    if ([defaultStoreURL checkResourceIsReachableAndReturnError:NULL])
    {
        NSFileManager *fileManager = [NSFileManager defaultManager];
        [fileManager copyItemAtURL:defaultStoreURL toURL:storeURL error:NULL];
    }
}

Answer 4

stringByAppendingPathComponent此方法是NSString类的实例方法。因此您不能在NSURL上访问此方法。

为了更正，请更改此行

NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @"ChildCare_v02.sqlite"];

通过此代码

 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"ChildCare_v02.sqlite"];

Answer 5

崩溃与核心数据无关。

似乎您正在调用一个不存在的方法。

在NSURL中，方法是“ URLByAppendingPathComponent”。

如果您需要stringByAppendingPathComponent，则在NSString中。

您很可能在构建过程中对此发出了警告。