var query = from person in people
            where person.Age == person.GetHashCode()
            select person;

let foo = item.Property.SomeNullableType

let foo = item.Property != null ? item.Property.SomeNullableType : null

//this is ok
var results = db.Orders
  .GroupBy( o => o.CustomerID )
  .Select(g => new
  {
    CustomerId = g.Key,
    OrderCount = g.Count()
  });

//this could be a lot of round trips.
var results = db.Orders
  .GroupBy( o => o.CustomerID )
  .Select(g => new
  {
    CustomerId = g.Key,
    OrderIds = g.Select(o => o.OrderId)
  });

// this is ok
// used ToList to separate linqtosql work from linqtoObject work
var results = db.Orders
  .Select(o => new {o.CustomerId, o.OrderId})
  .ToList()
  .GroupBy(o => o.CustomerId)
  .Select(g => new
  {
    CustomerId = g.Key,
    OrderIds = g.Select(o => o.OrderId)
  });