How to do a SQL "Where Exists" in LINQ to Entities?

I really want to do something like this:

Select * 
from A join B on A.key = B.key join C on B.key = C.key -- propagated keys
where exists (select null from B where A.key = B.key and B.Name = "Joe") and
      exists (select null from C where B.key = C.key and C.Name = "Kim")

What would the linq statement look like using Entity Framework 4 and C#?

Update:

Apparently .Contains() will produce "Where Exists" results. So, another attempt

(I don't know if this will even compile LOL):

var inner1 = from recordB in B
             where recordB.Name = "Joe"
             select recordB.key;

var inner2 = from recordC in C
             where recordC.Name = "Kim"
             select recordC.key;

var result = from recordA in A
             where inner1.Contains( recordA.key) &&
                   inner2.Contains( recordA.key)
             select recordA;

EDIT: WOW this is what actually worked:

var result = from A in Products
             where A.kfield1 == 1 && A.kfield2 == 2 &&
                   ( from B in Btable
                     where B.otherid == "Joe" &&  // field I want to select by
                           B.kfield1 == A.kfield1 &&     
                           B.kfield2 == A.kfield2 // Can keep adding keys here
                     select A.identifier  // unique identity field 
                   ).Contains(A.identifier) &&
                   ( from C in Ctable
                     where C.otherid == "Kim" &&  // field I want to select by
                           C.kfield1 == A.kfield1 &&     
                           C.kfield2 == A.kfield2 // Can keep adding keys here
                     select A.identifier  // unique identity field 
                   ).Contains(A.identifier)
             select A;

This produced this SQL:

SELECT [t0].[identifier], [t0].*
FROM [A] AS [t0]
WHERE ([t0].[kfield1] = @p0) AND ([t0].[kfield2] = @p1) AND (EXISTS(
    SELECT NULL AS [EMPTY]
    FROM [B] AS [t1]
    WHERE ([t0].[identifier] = [t0].[identifier]) AND ([t1].[otherid] = @p2) AND
          ([t1].[kfield1] = [t0].[kfield1]) AND 
          ([t1].[kfield2] = [t0].[kfield2]))) AND (EXISTS(开发者_开发百科
    SELECT NULL AS [EMPTY]
    FROM [C] AS [t2]
    WHERE ([t0].[identifier] = [t0].[identifier]) AND ([t2].[otherid] = @p3) AND
          ([t2].[kfield1] = [t0].[kfield1]) AND 
          ([t2].[kfiekd2] = [t0].[kfield2]) ))

Which is what I wanted. Notice the [t0].[identifier] = [t0].[identifier], which filters out null values because null doesn't compare equal to anything including itself (in SQL)

The .Any() extension method typically maps to exists.

Have you tried adding your exists conditioning to your joins?

from a in context.AEntity
Join B in context.BEntity on A.Key equals B.Key && B.Name == "Joe"
Join C in context.CEntity on B.Key equals C.Key && C.Name == "Kim";

Not sure if that will work, but worth a shot.