如何顯示「O」的年份和月份值，如果沒有記錄在表存在該月/年

Question

可能重複：
SQL Group and Sum By Month - Default to Zero

在我的表，我是沒有記錄一些月份和年份，所以我需要把'0'的記錄，並需要顯示所有月份和年份從'2006'到'2012'結果，請建議我

在此先感謝

Answer 1

虛擬纔是你真正的表...

WITH DummyDates (Date) AS (
    SELECT DATEADD(DAY, DATEDIFF(DAY, 0, '20121231') - DATEDIFF(DAY, '20060101', '20121231'), 0) 
     UNION ALL SELECT DATEADD(DAY, 1, Date) 
      FROM DummyDates 
      WHERE DATEADD(DAY, 1, Date) <= '20121231') 
SELECT DatePart(yy,DummyDates.Date) as [Year],DATEPART(MM,DummyDates.Date) as [Month],SUM(Case when dummy.date is null then 0 else 1 end) as cnt 
FROM DummyDates 
LEFT Join dummy on dummy.Date=DummyDates.Date 
Group by DatePart(yy,DummyDates.Date),DATEPART(MM,DummyDates.Date) 
Order by DatePart(yy,DummyDates.Date),DATEPART(MM,DummyDates.Date) 
OPTION (MAXRECURSION 0)