官网：https://realm.io/
1.说下数据库迁移的问题：
在func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
dataBaseMigration()//数据库迁移操作
}
//MARK:数据库操作
extension AppDelegate{
//MARK:数据库迁移
func dataBaseMigration()
{
let config = RLMRealmConfiguration.defaultConfiguration()
//第一个版本
//config.schemaVersion = 0
// config.migrationBlock = {
//(migration,oldSchemaVersion) in
// if oldSchemaVersion