实体框架一对一关系？

Question

I've generated my tables from my diagram :

Database schema But I dunno why, EF will generate this in the Origin model:

public virtual ICollection<Container> Containers { get; set; }

In the Container model :

public int OriginID { get; set; }
public virtual Origin Origin { get; set; }

and in the context :

modelBuilder.Entity<Origin>()
            .HasMany(e => e.Containers)
            .WithRequired(e => e.Origin)
            .WillCascadeOnDelete(false);

But a Container Object CAN ONLY have one Origin object.

How can I remove the collection to have only one instance of my object in the origin object ?

Because actually my Restier service is retrieving me origins objects with a collection of only ONE container.

So the collection is totally useless.

Do you guys have any idea?

Thank you very much

Answer 1

Because origins could well be related to a lot of containers - they don't know it. What you have is a one(origin) to many(container). Say I have origin with ID 1 and container A with originID 1. What would prevent me from adding container B with the same originID? If you insist on a 1-to-1 relation, try adding keys to both models - origin should know it's only related to the one container and vice-versa.

TD;DR: Add ContainerID to the Origin table.

Answer 2

i think that the best way to add a one-to-one relation is have a primary key that is also a foreign key.

( the Origin Id should reference the Container id)