I have problem with deleting related rows in Entity Framework 4.1. I have tables with relations
Book 1<--->* BookFormats
I have set the on delete cascade:
ALTER TABLE [dbo].[BookFormats] WITH CHECK ADD CONSTRAINT [FK_BookFormats_Book]
FOREIGN KEY([BookID]) REFERENCES [dbo].[Book] ([BookID]) on delete cascade
The EDMX property
Then, I want to remove the all BokFormats
items related to my Book
object:
var originalBook = m.db.Book.First(x => x.BookID == bookId);
originalBook.BookFormats.Clear();
m.db.SaveChanges();
But, I get the error:
The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.
I ran out of ideas on how to delete these objects. Any ideas?
You can use RemoveRange :
m.db.BookFormats.RemoveRange(originalBook.BookFormats);
m.db.SaveChanges();
But this is for EF 6.0