数据透视表视图的SQL连续列值

Question

我在表中有这样的数据结构:

Region | Date       | Value
A      | 01/01/2014 |    100
A      | 01/20/2014 |     50
A      | 01/02/2014 |    200
A      | 01/05/2014 |    300
B      | 01/01/2014 |    50
B      | 02/15/2014 |    70
B      | 02/25/2014 |    50
C      | 05/02/2014 |    70

我正在尝试使用T-SQL查询创建一个透视视图:

Region | Jan-2014 | Feb-2014 | Mar-014 | Apr-2014 | May-2014 | -> thru desired month-year
A      |    150   |   200    |   0     |     0    |    300   |
B      |     50   |   120    |   0     |     0    |      0   |
C      |      0   |     0    |   0     |     0    |     70   |

请注意，同一个月的多个值需要对给定地区进行汇总没有记录的月份仍然应该显示为零值的列(例如:March和April)

我累了使用枢轴选项，撤回等，但似乎不能得到这个工作任何帮助都是非常感谢的。

谢谢。

Answer 1

没有这些月份的结果的原因是您错过了要转到列中的日期。

有几种方法可以做到这一点。您可以硬编码查询的IN部分中的所有日期值，以便列显示:

select Region,
  isnull([Jan-2014], 0) [Jan-2014], isnull([Feb-2014], 0) [Feb-2014], 
  isnull([Mar-2014], 0) [Mar-2014], isnull([Apr-2014], 0) [Apr-2014],
  isnull([May-2014], 0) [May-2014], isnull([Jun-2014], 0) [Jun-2014], 
  isnull([Jul-2014], 0) [Jul-2014], isnull([Aug-2014], 0) [Aug-2014],
  isnull([Sep-2014], 0) [Sep-2014], isnull([Oct-2014], 0) [Oct-2014], 
  isnull([Nov-2014], 0) [Nov-2014], isnull([Dec-2014], 0) [Dec-2014]
from 
(
  select left(datename(month, t.date), 3) +'-'
            + cast(year(t.date) as char(4)) monthYear,
    t.region,
    t.value
  from yt t
) src
pivot
(
  sum(value)
  for monthYear in ([Jan-2014], [Feb-2014], [Mar-2014], [Apr-2014],
                    [May-2014], [Jun-2014], [Jul-2014], [Aug-2014],
                    [Sep-2014], [Oct-2014], [Nov-2014], [Dec-2014])
) piv;

参见SQL Fiddle with Demo。

另一种方法是创建一个可以在查询中使用的日期表。一旦创建完成，您就可以对表使用LEFT JOIN，这样您就可以返回您想要显示的所有日期。您可以创建一个递归查询来在PIVOT查询中生成该列表，或者用日期列表填充一个表。递归查询类似于:

;with dates (startDate, endDate) as 
(
  select min(date), cast('2014-12-31' as date)
  from yt
  union all
  select dateadd(m, 1, startDate), enddate
  from dates
  where month(startDate) + 1 <= month(enddate)
)
select startDate
from dates;

参见SQL Fiddle with Demo。如果将它连接到PIVOT，那么查询将是:

select *
from 
(
  select left(datename(month, d.startdate), 3) +'-'
            + cast(year(d.startdate) as char(4)) monthYear,
    t.region,
    t.value
  from dates d
  left join yt t
    on month(d.startdate) = month(t.date)
    and year(d.startdate) = year(t.date)
) src
pivot
(
  sum(value)
  for monthYear in ([Jan-2014], [Feb-2014], [Mar-2014], [Apr-2014],
                    [May-2014], [Jun-2014], [Jul-2014], [Aug-2014],
                    [Sep-2014], [Oct-2014], [Nov-2014], [Dec-2014])
) piv
where region is not null;

参见SQL Fiddle with Demo。您可以将其用作PIVOT查询的一部分，但是您仍然需要为PIVOT手工编写IN子句中的所有日期。

我猜你想使用这个查询的动态SQL版本，所以日期会根据你的需要而改变。动态版本将是:

DECLARE @cols AS NVARCHAR(MAX),
    @colsNull AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX),
    @startdate datetime = '2014-01-01',
    @enddate datetime = '2014-12-01'
;with dates (startDate, endDate) as 
(
  select @startdate, @enddate
  from yt
  union all
  select dateadd(m, 1, startDate), enddate
  from dates
  where dateadd(m, 1, startDate) <= enddate
)
select @cols = STUFF((SELECT ',' + QUOTENAME(left(datename(month, d.startdate), 3) +'-'
                                                      + cast(year(d.startdate) as char(4))) 
                    from dates d
                    -- where startdate >= '2014-01-01' and startdate <= '2014-06-01'
                    group by d.startdate
                    order by d.startdate
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,''),
    @colsNull = STUFF((SELECT ', isnull(' + QUOTENAME(left(datename(month, d.startdate), 3) +'-'
                                                      + cast(year(d.startdate) as char(4)))+', 0) as '+QUOTENAME(left(datename(month, d.startdate), 3) +'-'
                                                      + cast(year(d.startdate) as char(4)))
                    from dates d
                    -- where startdate >= '2014-01-01' and startdate <= '2014-06-01'
                    group by d.startdate
                    order by d.startdate
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 
        ,1,1,'')
from dates
set @query = 'SELECT region, ' + @colsNull + ' from 
             (
                  select left(datename(month, t.date), 3) +''-''
                            + cast(year(t.date) as char(4)) monthYear,
                    t.region,
                    t.value
                  from yt t
            ) x
            pivot 
            (
                sum(value)
                for monthyear in (' + @cols + ')
            ) p '
execute(@query);

参见SQL Fiddle with Demo。这个版本使用递归CTE生成将在动态sql字符串中使用的日期列表。即使您的数据表在显示的月份可能不存在，您仍然会有一个新列。

结果如下:

| REGION | JAN-2014 | FEB-2014 | MAR-2014 | APR-2014 | MAY-2014 | JUN-2014 | JUL-2014 | AUG-2014 | SEP-2014 | OCT-2014 | NOV-2014 | DEC-2014 |
----------------------------------------------------------------------------------------------------------------------------------------------
|      A |      650 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |
|      B |       50 |      120 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |
|      C |        0 |        0 |        0 |        0 |       70 |        0 |        0 |        0 |        0 |        0 |        0 |        0 |