如何使用t-sql将动态7天行转换为列

背景信息 我有一个400多行的大表，每天都在变化（一天的数据丢失，一天的数据丢失），表在“天”字段上分区，因此有31个分区。 表中的每一行都有类似的数据：

ID, Postcode, DeliveryPoint, Quantity, Day, Month
1   SN1 1BG   A1               6        29    1
2   SN1 1BG   A1               1        28    1
3   SN1 1BG   A2               2        27    1
4   SN1 1BG   A1               3        28    1
5   SN2 1AQ   B1               1        29    12
6   SN1 1BG   A1               2        26    12

我需要以以下格式提取7天的数据：

Postcode, Deliverypoint, 7dayAverage, Day1,day2,Day3,Day4,Day5,Day6,Day7  
SN1 1BG      A1             2          0    1    2    1    3    4   0

我可以很容易地提取7天期间的数据，但需要创建如上所示的专栏版本

我有这样的想法：

select postcode,deliverypoint,
sum (case  day when 23 then quantity else 0 end) as day1,
sum (case  day when 24 then quantity  else 0 end) as day2,
sum(case  day when 25 then quantity  else 0 end) as day3,
sum(case  day when 26 then quantity  else 0 end) as day4,
sum(case  day when 27 then quantity  else 0 end) as day5,
sum(case  day when 28 then quantity  else 0 end) as day6,
sum(case  day when 29 then quantity  else 0 end) as day7,
sum(quantity)*1.0/@daysinweek as wkavg
into #allweekdp
from maintable dp with (nolock)
where day in (select day from #days)
group by postcode,deliverypoint

其中#days具有7天期间的天数

但正如您所见，我已将日数硬编码到查询中，我想将其从临时表中取出#days，但找不到一种方法（这里最好是数组）

还是我完全错误地处理这件事

问候

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史蒂夫

如果我理解正确，我会做的是：

将日和月列转换为日期时间值

为每个日期获取一周的第一天和工作日的第几天（1-7），以及

在一周的第一天调整数据和分组

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请参见此处：

正如utexaspunk所建议的，Pivot可能是一条可行之路。我对pivot从来都不满意，我更喜欢手动旋转它，这样我就可以控制一切的外观，所以我使用了一种类似于您使用脚本来解决问题的解决方案。不知道我的方式和utexaspunk之间的性能会如何比较

Declare @Min_Day Integer = Select MIN(day) as Min_Day From #days;

With Day_Coding_CTE as (
Select Distinct day
    , day - @Min_Day + 1 as Day_Label

From #days
)

, Non_Columnar_CTE as (
Select dp.postcode
    , dp.deliverypoint
    , d.day
    , c.Day_Label
    , SUM(quantity) as Quantity

From maintable dp with (nolock)
    Left Outer Join #days d
        on dp.day = d.day --It also seems like you'll need more criteria here, but you'll have to figure out what those should be
    Left Outer Join Day_Coding_CTE c
        on d.day = c.day
)

Select postcode
    , deliverypoint
    , SUM(Case
        When Day_Label = 1
            Then Quantity
            Else 0
        End) as Day1
    , SUM(Case
        When Day_Label = 2
            Then Quantity
            Else 0
        End) as Day2
    , SUM(Case
        When Day_Label = 3
            Then Quantity
            Else 0
        End) as Day3
    , SUM(Case
        When Day_Label = 4
            Then Quantity
            Else 0
        End) as Day4
    , SUM(Case
        When Day_Label = 5
            Then Quantity
            Else 0
        End) as Day5
    , SUM(Case
        When Day_Label = 6
            Then Quantity
            Else 0
        End) as Day6
    , SUM(Case
        When Day_Label = 7
            Then Quantity
            Else 0
        End) as Day7
    , SUM(Quantity)/@daysinweek as wkavg

From Non_Columnar_CTE

Group by postcode
    deliverypoint