T-SQL CTE Sequence of Weeks [closed] - tsql

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I am trying to write a recursive CTE to give me a sequence of Mondays starting at the 38th week for the next 20 weeks over 6 years. I need to graph weekly sales data for the past 6 years and thought a recursive CTE would be the best method to dynamically create a sequence of Monday dates. It's a little complicated because the season continues into the next year. Here's an example of how I would like the recordset to look:
9/17/2012
9/24/2012
10/1/2012
10/8/2012
10/15/2012
10/22/2012
10/29/2012
11/5/2012
11/12/2012
11/19/2012
11/26/2012
12/3/2012
12/10/2012
12/17/2012
12/24/2012
12/31/2012
1/7/2013
1/14/2013
1/21/2013
1/28/2013
2/4/2013
2/11/2013
2/18/2013
2/25/2013
9/16/2013 <-next season start
9/23/2013
9/30/2013
10/7/2013
10/14/2013
10/21/2013
10/28/2013
11/4/2013
11/11/2013
11/18/2013
11/25/2013
12/2/2013
12/9/2013
12/16/2013
12/23/2013
12/30/2013
1/6/2014
1/13/2014
1/20/2014
1/27/2014
2/3/2014
2/10/2014
2/17/2014
2/24/2014
I don't know if this is possible, but it seems like it could be. I was thinking I might have to use multiple CTEs to accomplish this, but am really struggling how to do this. Any help or guidance is greatly appreciated.

Answer 1

So I figured it out. valverij's answer would have worked as well. Here's what I came up with using 2 recursive CTE's. If anyone sees anything wrong with it, let me know.
WITH Seasons(StartDate) AS
(
SELECT DATEADD(m, 4, DATEADD(yy, DATEDIFF(yy, 0, GETDATE()), 0)) AS StartDate UNION ALL
SELECT DATEADD(yy, -1, StartDate)
FROM Seasons
WHERE YEAR(StartDate) > YEAR(GETDATE()) - 6
),
Weeks(StartDate, WeekStartDate) AS
(
SELECT DATEADD(d, 1 - DATEPART(dw, DATEADD(wk, 20, Seasons.StartDate)), DATEADD(wk, 20, Seasons.StartDate)), DATEADD(d, 1 - DATEPART(dw, DATEADD(wk, 20, Seasons.StartDate)), DATEADD(wk, 20, Seasons.StartDate)) AS WeekStartDate
FROM Seasons UNION ALL
SELECT StartDate, DATEADD(wk, 1, WeekStartDate)
FROM Weeks
WHERE (WeekStartDate < DATEADD(wk, 23, StartDate))
)
SELECT StartDate, WeekStartDate
FROM Weeks
ORDER BY WeekStartDate DESC

Answer 2

If you're just looking for Mondays in a table, you can use DATENAME(WEEKDAY, [ColumnName]) to test for Mondays.
For example, the following code would find all of the Monday SaleDates in a hypothetical Sales table:
SELECT *
FROM Sales
WHERE DATENAME(WEEKDAY, SaleDate) = 'Monday'
From there, you could apply whatever additional conditions you need to (start date, end date, etc.)
Now, if you are just looking to generate a list of all Mondays, you can use a table variable and a WHILE loop:
DECLARE #Mondays TABLE(MondayDate datetime)
DECLARE #CurrentDate datetime = '02/07/2013' -- one year ago
WHILE #CurrentDate <= GETDATE() BEGIN
IF DATENAME(WEEKDAY, #CurrentDate) = 'Monday'
INSERT INTO #Mondays VALUES(#CurrentDate)
SET #CurrentDate = #CurrentDate + 1
END
SELECT *
FROM #Mondays
Either way, I definitely don't think you need CTE's to accomplish this.