T-SQL Select returning results for a period of time

I have tried but i am not able to figure this out. I have a table transactions (transaction_ID, transaction_Person_ID, Transaction_Date etc). What i want is to return all the transaction_person_ID's that have more than 3 transactions per week for the last year. That means i have to check for 1-1-10 to 7-10-10 to see if someone had more than 3 transactions that week, then for 2-1-10 to 8-10-10 etc etc. What i have written so far is this

WITH Dates AS (
        SELECT
         [Date] = CONVERT(DATETIME,'01/01/2010')
        UNION ALL SELECT
         [Date] = DATEADD(DAY, 1, [Date])
        FROM
         Dates
        WHERE
         Date < '12/31/2010'
)

SELECT transaction_person_开发者_StackOverflow中文版Id FROM transactions
JOIN DATES
ON transactions.transaction_date = dates.date
where transactions.Transaction_Date between dateadd(DAYOFYEAR,-7,dates.date) and dates.date
group by transaction_person_Id
having count(transaction_person_ID) >= 4
OPTION (MAXRECURSION 2000)

Thanks

I haven't got an instance of ms-sql to hand at the moment so I cant test this however it should do what you want once the inevitable syntax errors have been corrected

select 
    transaction_person_ID
from
(
    select 
        transaction_person_Id, 
        count(transaction_person_id), 
        datepart(wk,Transaction_date)
    from
        transactions
    Where
        Transaction_date > dateadd(d,-datepart(dy,getdate())+1,getdate())
    group by 
        transaction_person_Id, 
        datepart(wk,Transaction_date)
    having
        count(transaction_person_id) >3
) as foo
group by
   transaction_person_id
having
   count(transaction_person_id) >= datepart(wk,getdate)

Hope that helps!