LINQ to Dataset - Subquery

I am writing a query in LINQ and I am stuck with the subquery part.  

Original SQL:
SELECT account, bal_date, ccy, balance
FROM Balance A
WHERE
A.balance < 0 AND
A.date =  ( SELECT
        MIN(B.bal_date)
        FROM Balance B
        WHERE balance < 0 AND 
                     A.account = B.account AND
                     A.ccy = B.ccy
        )

LINQ:
Dim query = From bal In dt.AsEnumerable() _
                    Where bal.Item("balance") < 0 _
                    And bal.Item(“bal_date”) = ( subquery? )
                    Select bal


I learned that if I do Grouping by account and currency, I can get the MIN (bal_date),  but the I need the balance of such date, not the  MIN(balance) or MAX(balance).

I would appreciate if I get some help from Experts...
TakamasaAsked:
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Ramprakash JeyabalanCommented:
What do you mean "balance of such date"? Can you give an example?
0
TakamasaAuthor Commented:
Hi Ramprakash

Thank you for your comment.
I want to get the balance as of MIN(B.bal_date) - the result of the subquery.
0
Ramprakash JeyabalanCommented:
Try this please.
Dim query = From bal In dt.AsEnumerable() _
                    Where bal.Item("balance") < 0 _
                    And bal.Item("bal_date") = (from acc in dt.AsEnumerable()
                                                where acc.Item("account") == bal.Item("account")
                                                and acc.Item("balance") < 0
                                                select acc.Item("bal_date")).Min()
Select bal

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TakamasaAuthor Commented:
Ramprakash,

Thank you so much ! It worked.
0
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