实体框架 - 如何设置关联值？ [英] Entity Framework - How to Set Association Value?

问题描述

假设我有一个Person类和一个Order类，在DB中有外键。 EF模型将标记具有订单列表的Person，并使用Person实例订购。

如果我要为订单设置Person，我真的要做它有一个Person的实例？

是否没有一个减肥的方式这样做，只要一个PersonID？

解决方案

要将Person实体分配给一个没有加载Person实体的订单，你必须这样做：

  var db = new OneToManyEntities（）; 
 var Order = new Order {OrderId = 100，OrderName =Order name}; 
订单。 PersonReference.EntityKey = new EntityKey（OneToManyEntities.Person，PersonID，10）; 
 db.AddToOrders（Order）; 
 db.SaveChanges（）; 
  

Let's say I have a Person class and an Order class, with foreign keys in the DB. The EF model will mark Person with a List of Orders and Order with a Person instance.

If I want to set the Person for the Order, do I really have to do it with an instance of Person?

Is there not a slimmed down way to do so, say with just a PersonID ?

解决方案

To assign Person entity to a Order without loading Person entity, you have to do something like this:

var db = new OneToManyEntities();  
var Order  = new Order { OrderId = 100, OrderName = "Order name" };  
Order. PersonReference.EntityKey = new EntityKey("OneToManyEntities.Person ","PersonID",10);
db.AddToOrders(Order); 
db.SaveChanges();

这篇关于实体框架 - 如何设置关联值？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！