C# Unable to determine the principal end of the relationship

Question

foreach (var item in order.MyFiles)
{
   var newFile = adapter.db.File.CreateObject();

   newFile.Name = item.FileName;

   adapter.db.File.AddObject(newFile);

   adap         


        

Answer 1

This could be because of a cyclic reference in you EDMX back to the same table.

Means for example if EmployeeDepartment is the table that you are going to update and the Primary key is EmployeeDepartmentID and if it is identity column and auto-generated, Check in the EDMX whether the EmployeeDepartmentID is referenced back to itself. If so, right click on that foreigh key reference and click delete.

This worked for me and I hope this works for you as well.

Thanks,

Bibin.

Answer 2

You cannot use newFile.FileID when defining a new MyFile before saving changes. The FileID is default (0) until you save the new entity in database. You'd have to use navigation property of File in your MyFile class. EF will detect the relation and will commit data appropriately.

Try to change the line item.MyFile.Add(new MyFile { FileID = newFile.FileID }); with:

item.MyFile.Add(new MyFile { File = newFile });  

where File is the navigation property defined in MyFile entity.