违反主键限制-EF

Question

I have a problem trying to update a record in the DB. I am using EF 6.2.0 in C # with .NET 4.7.2.

public abstract class BaseEntity { }

public abstract class Entity<T> : BaseEntity, IEntity<T>
{
    //public virtual T Id { get; set; }
}

public class Order : Entity<long>
{
    public long OrderID { get; set; }

    ...
    ...
    ...

    public StatusEnum Status { get; set; }

    public virtual Option Options { get; set; } = new Option();

    public virtual ICollection<OrderDetail> Details { get; set; } = new List<OrderDetail>();
}

public class Option : Entity<long>
{
    public long OptionID { get; set; }

    ...
    ...
    ...

    public virtual Order Order { get; set; }
}

public class OrderDetail
{
    public long OrderDetailID { get; set; }

    ...
    ...
    ...

    public virtual Order Order { get; set; }
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    public DbSet<Order> Orders { get; set; }

    public DbSet<Option> Options { get; set; }

    ...
    ...
    ...

    modelBuilder.Entity<Order>()
        .HasOptional(x => x.Options)
        .WithRequired(x => x.Order);
}

using (var dbContext = new Context())
{
    var dbItem = dbContext.Orders.FirstOrDefault(...);
    if (dbItem != null)
    {
        dbItem.Status = StatusEnum.New;
        dbItem.Details.Add(orderDetail);
        dbContext.SaveChanges();
    }
}

When I try to update I get the following error

"Violation of PRIMARY KEY restriction 'PK_dbo.Option' Unable to insert a key duplicated in object 'dbo.Option'. The value of the duplicate key is (1). \ R \ nIf finished the instruction. "

I do not understand why try to add another "Option" record with the same ID

Something I saw is that at the time of obtaining the database record, Options comes with the correct data, but OrderID is 0, when it would have to be 1 (In the DB it has a 1)

What is the problem? Thx!

Answer 1

You don't show that part of the code, but I assume that your OrderDetail entity has a dependant navigation property Order . Now when EF begins to track OrderDetail after you added it, EF by default recursively also marks all its related entities (unless already tracked) as added. In this case the state of Options are set to added via pricipal entity Order , so EF tries to insert them into database.
A solution to this would be either to:
1) not set/unset the Order principal navigation property, but set only the foreign key OrderId ;
2) call update on principal entity Order (in this case be sure that your Options are tracked in the proper state or navigation property is unset or else you might end up with the same exact problem).

An excellent material on this: https://msdn.microsoft.com/en-us/magazine/dn166926.aspx

EDIT: apparently I'm blind because I missed the OrderDetail entity part. Well, at least I didn't miss my guess about the navigation property being there. :D