Simply adding DefaultIfEmpty() to the inner join syntax does the trick, although you spent so much time deprecating it in the original article.

Response: My goal is to get LINQ users to think in terms of object graphs rather than relational sets. It’s a critical difference which many miss because LINQ looks so much like SQL. But if your goal is to throw the results into a visual control designed for a relational set, then there’s nothing particularly wrong with it.

I find it quite reasonable to want a result set that looks like

select t1.ContactName, t2.Freight from Customers t1
left join Orders t2 on t1.CustomerID = t2.CustomerID

Response: I don’t think so, but then again, my goal is not to "immediately chuck the result set into a DataGridView." Yours might be, which is fine, but that just means your needs are different than mine. As for how to meet your needs, read on…

In the self referencing Table Employees the field ReportsTo is nullable and actually contains nulls.
It is unusual for a foreign key to be nullable between 2 SEPARATE tables.
Try left joining Customers and Orders.
Although CustomerID in Orders is nullable, there are no Orders without a CustomerID.

Response: Not in the data delivered with Northwind, no, but it’s certainly possible.

If Orders is the left table, an inner join and an outer join produce the same result anyway, and yield only those customers who have placed orders.
If Customer is the left table, the fields of Customer.Order are inaccesible.

Response: That is wrong, on several counts. First, the property is Orders, not Order. It’s 1..*, not 1..1. Second, you certainly can use the properties of Orders in a query. The following query works fine, for example:
var q = from c in context.Customers
from o in c.Orders
select new
{
Name = c.ContactName,
Freight = o.Freight
};

It requires a nested foreach to convert the result set to a List.

Response:No. What I think you’re trying to say is "I don’t know how to convert the result to a "flattened, SQL-like" tabular result set instead of an "object-like," hierarchical tree of customers and orders without a nested foreach (or a join). But it’s quite possible. I’ve already shown the "inner join" version above. Here’s the "left join" version:
var q = from c in context.Customers
from o in c.Orders.DefaultIfEmpty()
select new
{
Name = c.ContactName,
Freight = o.Freight
};

I wouldn’t describe this as an improvement over ‘join’ where I can immediately chuck the result set into a DataGridView.

Response:See the query above. This isn’t how I’d do it, because most use cases of such tabular result forms tend to want to group them back into hierarchies anyway (think of every reporting tool ever created). But it’s certainly possible. And again, the join is just noise. The association properties make it redundant and messy.

Maybe you have an elegant solution to left joining Customers with Orders, i.e showing ALL Customers with or without Order details ?

I think, the angle brackets (for generics code my my pasted code) is being removed while rendering html (I mean I pasted the full code but found that the "" are not coming.
Pasting the line again below,

"TPair= class // declares TPair type with two type parameters"

Am I missing anything? Could you please explain reg. the discrepancy?

Response: Because the comma and the semicolon mean different things. Read Rudy’s comment above (plus the discussions which follow); does that explain it for you?

Delphi 2010 help section
=================
ms-help://embarcadero.rs2010/rad/Overview_of_Generics.html

Code Example
==========
type
TPair= class<TKey; TValue> // declares TPair type with two type parameters

type
TSIPair = TPair; // declares instantiated type
TSSPair = TPair; // declares with other data types
TISPair = TPair;
TIIPair = TPair;
TSXPair = TPair;

I think a lot of people have missed the significance of:

from s in context.Employees
from e in s.Employees

as a way of doing joins. Once you understand what you’re looking at, it’s obvious and makes perfect sense. It might make sense to highlight this in a future post. And again, thanks for the SO help.

I’ve tried to disable the DEP (Changing the Boot.ini value from /noexecute=OptOut to AlwaysOff
But no sign that it helped.

Any other idea ?

Thanks,Udi

Response: Yes, several other ideas.

from p in entities.Parent
select new PresentationParent {
ID = p.ID,
Name = p.Name,
Age = p.Age,
Children = (from c in p.Children
select new PresentationChild {
ID = c.ID,
Name = c.Name,
Age = c.Age
}).ToList()
}

I get an exception at runtime when I try to enumerate the results that LINQ to Entities "doesn’t recognize" the ToList() method. It works fine if I’m using LINQ to SQL. Is there a way to do this using LINQ to Entities?

Response: Your ToList is in the wrong place. Try:

from p in entities.Parent
select new PresentationParent {
ID = p.ID,
Name = p.Name,
Age = p.Age,
Children = (from c in p.Children
select new PresentationChild {
ID = c.ID,
Name = c.Name,
Age = c.Age
})
}).ToList();