Adding Reference To Owning Object In Ef Core

Question

I have two entities: Job and Orderable on our code-first database: The (extremely simple) models of these two are: class Job { public Guid Id {get; set;} public string JobName {get; set;} public List Items {get; set;} } class Orderable { public Guid Id {get; set;} public string MaterialNumber {get; set;} } I wanted to be able to reference the Job from the orderable, so I added a property like so: public Job OwningObject {get; set;} But when I did the migration, it created a second foreign key for this object. Now, it seems that if I am getting the Orderables from the Job, it uses key1, but if I am getting the Job from the Orderable, it uses key2. Within our OnmodelCreating method in our context we have added the following before the key was created, which I thought was required to make it work, but I am not sure if this is potentially causing the issue. modelBuilder.Entity().HasMany(x => x.Items).WithOne(); We were able to force the key to reference the proper field with a data annotation of: [ForeignKey("OwningObjectId1")] But this feels hacky and I don't like it as a permanent solution. JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

EF uses shadow properties to persist the foreign key relationship when no explicit foreign key property is applied. The best thing to do is simply have explicit foreign key properties: [ForeignKey(nameof(OwningObject)] public Guid OwningObjectId { get; set; } public Job OwningObject { get; set; } If you're going to rely on shadow properties, then you need to actually think through what you're doing. First, when you use WithOne(), with no param, it's going to create a shadow property based on the related entity, which is Job. As a result, you'll get a column, JobId. When you have a reference property, it's going to assume a foreign key column based on the name of that property: OwningObjectId. Essentially, the combination of a reference property and using WithOne() and not referencing that property in the param, actually creates two separate one to many relationships. This can be easily corrected by simply telling EF which property to use explicitly: modelBuilder.Entity().HasMany(x => x.Items).WithOne(x => x.OwningObject);