Question

我有一个事件和日期列表以及它们，yyyy-mm-dd然后是一个类别。

我需要按一年中的每个月的类别（超速罚单，DUI等）订购。

这就是两列的样子

2002-12-28  No Driver License
2002-12-28  Hazardous Violations
2002-12-28
2002-12-28  Speeding    
2002-12-28  DUI
2002-12-28  Reckless Driving
2002-12-28      
2002-12-28  Speeding

这是我到目前为止所拥有的

SELECT
     [Date]
    ,[categoryId]   
     = (SELECT tertiary FROM [MSDAS].[dbo].[activity_categories] AS C 
        WHERE C.categoryId = A.categoryId)
    ,[value]

FROM [MSDAS].[dbo].[hp_activities] AS A 
    JOIN [MSDAS].[dbo].[workdays] AS W ON W.workdaysId = A.workdaysId

WHERE W.date IS NOT NULL 
    AND W.date >= '2002/1/1'

ORDER BY Date

Answer 1

SELECT innerSelect.dateMonth
, innerSelect.dateYear

FROM (SELECT (MONTH(yourTable.Date)) AS dateMonth
           , YEAR(yourTable.Date) AS dateYear
        FROM yourTable) AS innerSelect

GROUP BY innerSelect.dateMonth, innerSelect.dateYear

Answer 2

http://sqlfiddle.com/#!9/badf7/1

SELECT sum(id),
       category,
       year(t) y,
       month(t) m
FROM table
GROUP BY category, y, m;

我在添加样本数据之前做了准备，所以类别是数字的（无论如何要将其标准化，有一个单独的类别表并且只保留category_id）

这就是我按月和按年分组理解的内容。

编辑：在问题从mysql重新绑定到sql server之前回答

按月和年份分组给出yyyy-mm-dd作为日期

2 个答案: