EXIST w LINQ

Niedawno szukałem w jaki sposób generować za pomocą LINQ klauzulę EXIST.
Otóż istnieje prosty wzorzec na generowanie tej klauzuli:

Code:

            using (var context = new AdventureWorksLT2008R2Entities())
            {
                var q = from p in context.Product
                        where context.Product.Any(x => x.ListPrice > 1490)
                        select p;
                var sql = ((ObjectQuery) q).ToTraceString();
            }

Kluczem jest tutaj metoda Any. Właśnie ta metoda tworzy klauzulę EXIST, jeżeli chcemy uzyskać NOT EXIST wystarczy zaprzeczyć.

Wygenerowany SQL ma następującą postać:

SELECT

[Extent1].[ProductID] AS [ProductID],

[Extent1].[Name] AS [Name],

[Extent1].[ProductNumber] AS [ProductNumber],

[Extent1].[Color] AS [Color],

[Extent1].[StandardCost] AS [StandardCost],

[Extent1].[ListPrice] AS [ListPrice],

[Extent1].[Size] AS [Size],

[Extent1].[Weight] AS [Weight],

[Extent1].[ProductCategoryID] AS [ProductCategoryID],

[Extent1].[ProductModelID] AS [ProductModelID],

[Extent1].[SellStartDate] AS [SellStartDate],

[Extent1].[SellEndDate] AS [SellEndDate],

[Extent1].[DiscontinuedDate] AS [DiscontinuedDate],

[Extent1].[ThumbNailPhoto] AS [ThumbNailPhoto],

[Extent1].[ThumbnailPhotoFileName] AS [ThumbnailPhotoFileName],

[Extent1].[rowguid] AS [rowguid],

[Extent1].[ModifiedDate] AS [ModifiedDate]

FROM [SalesLT].[Product] AS [Extent1]

WHERE  EXISTS (SELECT

    1 AS [C1]

    FROM [SalesLT].[Product] AS [Extent2]

    WHERE [Extent2].[ListPrice] > cast(1490 as decimal(18))

)