TSQL to LINQ conversion reference?

I'm trying to find a good reference to help me convert this TSQL statement to Linq:

EXAMPLE:

SELECT * FROM Categories WHERE ProductID IN (SELECT ProductID FROM ProductCategories WHERE CatID = 23)

I can't find anywhere that references how to do the WHERE "IN" part.

From stackoverflow

• While it's not exactly a TSQL to LINQ reference, I have found the 101 LINQ Samples page on MSDN helpful for this purpose.

  See also this related question

  EdenMachine : Thanks - is this: http://msdn.microsoft.com/en-us/vcsharp/aa336761.aspx#intersect2 what I'm looking for? TSQL "IN" = Linq "Intersect"?

  EdenMachine : Ooops - I just now saw your "this related question" which gave me the answer I was looking for.

• See if this works:

  var qry = from c in Categories
            where (from pc in ProductCategories where pc.CatID = 23 select pc.ProductID).Contains(c.ProductID)
            select c;
  

  I don't know if there is a direct translation of the IN WHERE part in LinqToSQL (didn't found any reference) but I replaced that with a Contains.

• Using extension methods...

  var productIDs = context.ProductCategories
                          .Where( c => c.CatID == 23 )
                          .Select( c => c.ProductID );
  var categories = context.Categories
                          .Where( c => productIDS.Contains( c => c.ProductID ) );
  

  EDIT: 101 Linq Samples is a pretty good reference for simple things. For more complicated stuff I find that I usually have to resort to Google. FYI, if you want to search StackOverflow, I've found that it works better to use google and specify site: stackoverflow.com. YMMV.