The object [Book [Id=-2, EntityState=New]] could not be saved because it is invalid.

Hi, I have a simple application and database schema, which has a problem I can't figure out. The database schema is such

The LightSpeed Model looks like this

My code creates a book, then adds the book to the Member which is passed into the method.

var book = new Book{ Isbn = collection["Book.Isbn"], Name = collection["Book.Name"], Publisher = unitOfWork.Publishers.Single(m=>m.Id == int.Parse(collection["Book.Publisher.Id"])), AddedDate = DateTime.Now }; unitOfWork.Add(book); member.Books.Add(book); unitOfWork.SaveChanges();

An exception is thrown when calling unitOfWork.SaveChanges()

The object [Book [Ide=-2, EntityState=New]] could not be save because it is invalid. The errors are:
MembersBooks item 0 is invalid
Member is invalid
Reviews item 0 is invalid
Book is required
Publisher is invalid
Books item 0 is invalid

This code should work, but doesn't. I have looked through the properties of each of the entities and don't see anything that catches my eye.

Any suggestions and advice would be much appreciated.

Thanks, James

Hi James,

Nothing wrong with the code itself, but the member you are assigning it to has a Review associated which does not have a Book assigned causing it to be invalid, which in turn causes your Member to be invalid, which in turn causes your newly added Book to be invalid.

The object [Book [Ide=-2, EntityState=New]] could not be save because it is invalid. The errors are:
MembersBooks item 0 is invalid
Member is invalid
Reviews item 0 is invalid
Book is required
Publisher is invalid
Books item 0 is invalid

Jeremy