I want to create a new row in my database on a table that has a couple of foreign key relationships and I haven't been able to get a handle on what order and what calls need to be made. This is what I have so far:
db.Models.Order order = DB.Models.Order.CreateOrder( apple ); order.CustomerReference.Attach( ( from c in db.Customer where c.Id == custId select c ).First() ); db.SaveChanges();
The code is failing on the second line there, saying:
Attach is not a valid operation when the source object associated with this related end is in an added, deleted, or detached state. Objects loaded using the NoTracking merge option are always detached.
(Thanks John for the grammar fixes)
So I figured it out. This is what you have to do:
db.Models.Order order = DB.Models.Order.CreateOrder( apple ); order.Customer = (from c in db.Customer where c.Id == custId select c).First(); db.SaveChanges();
I hope that helps people.
Why not use entity references? Your method will cause an extra
A much nicer way is to use the
CustomerReference class and an
order.CustomerReference = new System.Data.Objects.DataClasses.EntityReference<Customers>(); order.CustomerReference.EntityKey = new EntityKey("ModelsEntities.Customers", "Id", custId);