Summarise by week, even for empty rows

Question

I want to summarise the sum of sales.quantity by week, and to show the week number even if there are no sales.

I have setup a weeks table with 1-54 in there to use an ou

Answer 1

I prefer this method versus a sub-select

SELECT Weeks.WeekNum, SUM(sales.quantity) AS sales
FROM Weeks
LEFT OUTER JOIN  sales ON (Weeks.WeekNum = DATEPART(week, sales.transDate) AND sales.transDate BETWEEN @fromDate AND @toDate)
GROUP BY Weeks.WeekNum