How to get table A and count of table B with Linq to Sql group by - linq-to-sql

Question

I have a Linq to SQL query that I want to return select columns from all matching rows from one table (TableC in my simplified query below) and a count of matching rows in another table (TableB in below). Certain other tables need to be involved too for the where clause to work (removed in simplified query).
How do I get the columns I need from TableC and a count of TableB?
This is a simplified version of my query:
var q = from a in dc.TableA
from b in dc.TableB
join c in dc.TableC on b.TableBID equals c.ID
join d in dc.TableD on a.ID equals d.TableAID
where 1 == 1 //lots of interesting stuff here
group c by new { b, c } into g
select new
{
ID = g.Key.c.ID,
Name = g.Key.c.Name,
Count = g.Count()
};
Update: I think I found a solution using group joins - answer posted below. I would still like to know if that was the right solution.

Answer 1

I came up with this solution after reading about Linq group joins.
var q = from a in TableC
join b in (from c in TableB
where (from d in TableA
join f in TableD on d.ID equals f.ID
where 1 == 1 //for simplicity
select d).Any()
&& 1 == 1 //more simplification
select c) on a.TableBID equals b.ID into g
where 1 == 1 //more simplification
select new
{
a.ID,
a.Name,
Count = g.Count()
};