Join Subquery result in Linq - sql

Question

I am posting one more doubt of mine:
Is there a way by which we can use the result of one query and then join the same further just like we do in SQL:
SELECT Applications.* , ApplicationFees.ApplicationNo, ApplicationFees.AccountFundDate1,ApplicationFees.AccountFundDate2 ,ApplicationFees.AccountFundDate3 , ApplicationFees.AccountCloseDate1, ApplicationFees.AccountCloseDate2,ApplicationFees.AccountCloseDate3,
isnull(SUBQRY11.AMNT ,0) as SCMSFEE1R,
isnull(SUBQRY12.AMNT,0) as SCMSFEE2R,
Left Join
(
SELECT ApplicationNo,COUNT(ApplicationNo) AS CNT, SUM(Amount) as AMNT
FROM Payments where (FEETYPE=1 AND FeePosition=1) and (FeeDate>='2011-01-01')
and (FeeDate<='2012-01-01')
GROUP BY ApplicationNo
)SUBQRY11
ON ApplicationFees.ApplicationNo= SUBQRY11.ApplicationNo
Left Join
(
SELECT ApplicationNo,COUNT(ApplicationNo) AS CNT2, SUM(Amount) as AMNT
FROM Payments where (FEETYPE=1 AND FeePosition=2) and (FeeDate>='2011-01-01')
and (FeeDate<='2012-01-01')
GROUP BY ApplicationNo )SUBQRY12 ON ApplicationFees.ApplicationNo=SUBQRY12.ApplicationNo
I want to avoid the same in foreach of the query as that will be quite time consuming.

Answer 1

Yes, you can join sub queries. Like this:
var query = from f in db.ApplicationFees
join sub in (from p in db.Payments
where p.Type == 1 && p.Position == 1 &&
p.Date >= fromDate && p.Date <= toDate
group p by p.ApplicationNo into g
select new {
ApplicationNo = g.Key,
CNT = g.Count(),
AMNT = g.Sum(x => x.Amount)
})
on f.ApplicationNo equals sub.ApplicationNo into feePayments
select new { Fee = f, Payments = feePayments };
But writing it in single query is not very maintainable. Consider to compose your query from sub-queries defined separately:
var payments = from p in db.Payments
where p.Type == 1 && p.Position == 1 &&
p.Date >= fromDate && p.Date <= toDate
group p by p.ApplicationNo into g
select new {
ApplicationNo = g.Key,
CNT = g.Count(),
AMNT = g.Sum(x => x.Amount)
};
var query = from f in db.ApplicationFees
join p in payments
on f.ApplicationNo equals p.ApplicationNo into feePayments
select new { Fee = f, Payments = feePayments };