//第一种方法全部加载
//nil表示从主bundles中加载对应的模型实体,其实会把程序中得所有的实体都加载了
NSManagedObjectModel *model=[NSManagedObjectModel mergedModelFromBundles:nil];
for (NSEntityDescription *desc in model.entities) {
NSLog(@"%@",desc.name);
}
//第二种方法
//从应用程序包中加载模型文件
// NSURL *modelUrl= [[NSBundle mainBundle] URLForResource:@"Model" withExtension:@"momd"];
// NSManagedObjectModel *model=[[NSManagedObjectModel alloc]initWithContentsOfURL:modelUrl];
//通过模型 和数据库持久化
NSPersistentStoreCoordinator *psc=[[NSPersistentStoreCoordinator alloc]initWithManagedObjectModel:model];
//持久化到coredata中
NSString *docs=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSURL *url=[NSURL fileURLWithPath:[docs stringByAppendingPathComponent:@"person.db"]];
NSError *error=nil;
NSPersistentStore *store=[psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url
options:nil error:&error];
if (store==nil) {
[NSException raise:@"添加数据库错误" format:@"%@",[error localizedDescription]];
}
NSManagedObjectContext *context=[[NSManagedObjectContext alloc]initWithConcurrencyType:NSMainQueueConcurrencyType];
context.persistentStoreCoordinator=psc;
NSManagedObject *person = [NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:context];
// 设置Person的简单属性
[person setValue:@"fengxin" forKey:@"name"];
[person setValue:[NSNumber numberWithInt:27] forKey:@"age"];
// 传入上下文，创建一个Card实体对象
NSManagedObject *card = [NSEntityDescription insertNewObjectForEntityForName:@"Card" inManagedObjectContext:context];
[card setValue:@"4414241933432" forKey:@"no"];
// 设置Person和Card之间的关联关系
[person setValue:card forKey:@"card"];
// 利用上下文对象，将数据同步到持久化存储库
NSError *error1 = nil;
BOOL success = [context save:&error1];
if (!success) {
[NSException raise:@"访问数据库错误" format:@"%@", [error1 localizedDescription]];
}
//下面是查询
NSFetchRequest *request=[NSFetchRequest fetchRequestWithEntityName:@"Person"];
NSArray *results= [context executeFetchRequest:request error:&error];
for (NSManagedObject *mode in results) {
NSLog(@"%@",mode);
}
