按月和类型计算记录

Question

我在SQL Server 2014中有一个使用此模式的表:

OccuredDate (date)     TypeID (int)
2014-1-1               1
2014-1-2               1
2014-2-5               4
2015-5-23              2
2015-6-3               3

...它有数千行由日期和类型ID组成,跨越多年.

因此,我可以将其绘制到图表组件,我正在尝试构建一个查询,在给定年份1)每月返回一行2)计算给定TypeID的TypeID实例的总数.图表组件更喜欢列类型计数.

所以对于"2014",它看起来像这样:

MonthDate    TypeOne    TypeTwo    TypeThree    TypeFour
2014-1-1     2          0          0            0
2014-2-1     0          0          0            1

要么:

Year    Month    TypeOne    TypeTwo    TypeThree    TypeFour
2014    Jan       2          0          0            0
2014    Feb       0          0          0            1

花了大半夜的时间,但没有运气.是否有一些黑暗的SQL魔法可以做到这一点？

谢谢!

Answer 1

您可以使用pivot来实现,具体如下:

SELECT OccuredDate, [1], [2], [3], [4]
FROM
(
    SELECT OccuredDate, TypeID FROM Table1) AS SourceTable
PIVOT
(
    count(TypeID) FOR TypeID IN ([1], [2], [3], [4])
) AS PivotTable

每月版本:

SELECT 
  DATEADD(month, DATEDIFF(month, 0, OccuredDate), 0) as Month,
  sum([1]) as [1], 
  sum([2]) as [2], 
  sum([3]) as [3], 
  sum([4]) as [4]
FROM
(
    SELECT OccuredDate, TypeID FROM Table1) AS SourceTable
PIVOT
(
    count(TypeID) FOR TypeID IN ([1], [2], [3], [4])
) AS PivotTable
group by 
  DATEADD(month, DATEDIFF(month, 0, OccuredDate), 0)

您可以在SQL Fiddle中进行测试:每日和每月

编辑:重写每月SQL