与具有相同模式的2个独立的数据库之间的复制的实体,我需要使用实体框架4.使用实体框架数据库
我创建2个上下文从一个数据库复制实体(记录)到另一个,但我收到以下错误,当我添加一个实体到第二语境:
An entity object cannot be referenced by multiple instances of IEntityChangeTracker.
我知道我不能避免错误,如果我使用分离的方法,但在这种情况下,相关的实体都将丢失!
示例代码:
var cx = new MyEntities();
//eager load related tables
var allEntities = from x in cx.Reservation.Include("Detail.MoreDetail")
select x;
// new instance of context but connected to a second database
var cx2 = new MyEntities(new ConnectionString...);
foreach (var e in allEntities)
{
//cx.Detach(reservation); // can't detach, or related entities will be lost
cx2.AddToReservation(reservation); // error happens here!
cx2.SaveChanges();
}
我怎么能执行这样的操作? 或者,我如何分离实体而不丢失相关实体?
相当不错的有用的,谢谢 – fernandoespinosa 2012-09-27 15:00:59