Using the All operator

I would like to see an example that makes the best use of the ALL operator when using a parent child reltaionship in LINQ. Can you show me one please?

From stackoverflow

• If you want to get the parents along with whether all its childrens are active.

  from p in MyContext.Parents
  select new
  {
     p,
     ChildrensActive = p.Childrens.All(c=> c.IsActive)
  }
  

• The All() extension method checks a predicate against all the items; for example, at execution:

  if(order.Lines.All(l=>l.IsClosed)) order.Close();
  

  (checks all lines are closed, and if so, closes the order)

  of in a query:

  var qry = from order in ctx.Orders
           where order.CustomerId = id
           select new {
              order.OrderId,
              IsShipped = order.Lines.All(l => l.IsShipped)
           };
  

  Viks : How would I handle a case where select all Customers having Order ..is this is a good candidate for 'All'?

  Marc Gravell : no; that would be Any - i.e. from cust in ctx.Customers where cust.Orders.Any() select cust;

• Many LINQ examples here: http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx

• IEnumerable<CD> goodCDs = CDs
    .Where(cd => cd.Songs.All(song => song.Rating > 6))