Question

I’ve got a very basic database schema and have created a dbml from it. Two tables are related in a one-to-many. (A)1-*(B) … hence each A gets an EntitySet called “BSet”.

If I do:

foreach (var a in db.A)
{
  Console.WriteLine(a.Name);
  foreach (var b in a.BSet)
  {
     Console.WriteLine(b.Number);
  }
}

I find that it prints out the same set of B’s for each A. If I debug the L2S SQL Log I can see its creating the correct SQL each time it calls BSet. In spite of that it prints the same set of Bs for each A.

If I write a LINQ Select statement then I get the correct result.

Whats broken in the foreach? I am usually pretty good with LINQs subtleties but this one is confusing me!

Answer 1

The problem was because the B table did not have a primary key correctly setup.

I had added a primary key for the field which I believed was the primary key, but was actually not.