我会用这个:

SELECT  Closing_Date = DATEADD(MONTH, DATEDIFF(MONTH, 0, Closing_Date), 0), 
        Category,  
        COUNT(Status) TotalCount 
FROM    MyTable
WHERE   Closing_Date >= '2012-02-01' 
AND     Closing_Date <= '2012-12-31'
AND     Defect_Status1 IS NOT NULL
GROUP BY DATEADD(MONTH, DATEDIFF(MONTH, 0, Closing_Date), 0), Category;

这将按每个月的第一天分组，所以

This will group by the first of every month, so

`DATEADD(MONTH, DATEDIFF(MONTH, 0, '20130128'), 0)` 

将给出 '20130101'.我通常更喜欢这种方法，因为它将日期作为日期.

will give '20130101'. I generally prefer this method as it keeps dates as dates.

或者你可以使用这样的东西:

Alternatively you could use something like this:

SELECT  Closing_Year = DATEPART(YEAR, Closing_Date),
        Closing_Month = DATEPART(MONTH, Closing_Date),
        Category,  
        COUNT(Status) TotalCount 
FROM    MyTable
WHERE   Closing_Date >= '2012-02-01' 
AND     Closing_Date <= '2012-12-31'
AND     Defect_Status1 IS NOT NULL
GROUP BY DATEPART(YEAR, Closing_Date), DATEPART(MONTH, Closing_Date), Category;

这真的取决于你想要的输出是什么.(在您的示例中不需要关闭年份，但如果日期范围跨越年份边界，则可能需要).

It really depends what your desired output is. (Closing Year is not necessary in your example, but if the date range crosses a year boundary it may be).