I had to define a recursive relationship on a composite key. After much trials, I ended up with this:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Category>()
.Property(t => t.WhichAmazon).HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
modelBuilder.Entity<Category>()
.Property(t => t.IdCategory).HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
modelBuilder.Entity<Category>()
.HasKey(c => new {c.WhichAmazon, c.IdCategory})
.HasOptional(p => p.Children)
.WithMany()
.HasForeignKey(c => new { c.WhichChildrenAmazon, c.ChildrenId });
}
for this table
public class Category
{
// Keys and relationships defined in BooksDataLayer
[MaxLength(2)]
public string WhichAmazon { get; set; }
public int IdCategory { get; set; }
public string Name { get; set; }
[Timestamp]
public Byte[] TimeStamp { get; set; }
public DateTime LastCheck { get; set; }
public virtual List<Book> Books { get; set; }
public string WhichChildrenAmazon { get; set; }
public int? ChildrenId { get; set; }
public virtual List<Category> Children { get; set; }
}
While trying to Add-Migration I was constantly having the same error: "Sequence contains no elements". As I was "almost" sure this definition was right, I went ahead a re-created a new Db, WITHOUT migration. Was perfectly OK, no problems with the Db at all. So there is "something" in there which EF 6 does not like. I had a confirmation, as EF power tools bombs if I try to get a schema "Exception has been thrown by the target of an invocation".
I'll see what happens now with migration if I restart from there, but I am afraid to not be able to use anymore with this Db. I do like the tool, a lot, so I hope this can be fixed.
