LINQ to SQL - How to add a where clause to a left join?

Question

This LINQ query expression emits a left join and works:

from p in Prices
join ip in ItemPrices 
    on new { p.PriceId,  ItemId = 7 } equals 
       new { ip.PriceId, ip.ItemId }
into priceItemPrice
from pip in priceItemPrice.DefaultIfEmpty()
select new
{
    pricesPriceId = p.PriceId,
    z = (int?)pip.PriceId,
    p.Content,
    p.PriceMinQ
}

SQL emitted:

-- Region Parameters
DECLARE @p0 Int = 7
-- EndRegion
SELECT [t0].[priceId] AS [pricesPriceId], 
    [t1].[priceId] AS [z], 
    [t0].[price] AS [Content], 
    [t0].[priceMinQ] AS [PriceMinQ]
FROM [price] AS [t0]
LEFT OUTER JOIN [itemPrice] AS [t1] 
    ON ([t0].[priceId] = [t1].[priceId]) 
    AND (@p0 = [t1].[itemId])

How can I get it to emit the SQL below? It just has the where clause tacked on the end. A where clause is not accepted under the "from pip" and a where lambda expression before DefaultIfEmpty() doesn't work. I know I can filter it out in the select, but that's not what I need.

SELECT [t0].[priceId] AS [pricesPriceId], 
    [t1].[priceId] AS [z], 
    [t0].[price] AS [Content], 
    [t0].[priceMinQ] AS [PriceMinQ]
FROM [price] AS [t0]
LEFT OUTER JOIN [itemPrice] AS [t1] 
    ON ([t0].[priceId] = [t1].[priceId]) 
    AND (@p0 = [t1].[itemId])
WHERE [t1].[priceId] is null

Update Oy vey, my mistake, the where clause did work - for some reason VS2008 was not behaving and giving me grief and my stomach was growling. I tested back in LinqPad and the where clause was fine. So this little addition did work:

...
from pip in priceItemPrice.DefaultIfEmpty()
*** where pip.ItemId == null ***
select new
...

Answer 1

Here is a sample of how OneDotNetWay has done something similar. I've tried to take their example and match up your query.

var query =  p in Prices
   join ip in ItemPrices 
   on 
   new { p.PriceId,  ItemId = 7 } 
   equals 
   new { ip.PriceId, ip.ItemId }
   into priceItemPrice
   from pip in priceItemPrice.DefaultIfEmpty()
   select new
   {
      pricesPriceId = p.PriceId,
      z = (int?)pip.PriceId,
      p.Content,
      p.PriceMinQ
   }