当时间不在轴上时出现 ParallelPeriod 问题

Question

此查询中计算的成员 [Amount LM]（=amount last month）有什么问题？如果我在行上指定时间似乎有效，但如果我不指定时间则失败，即使我在 where 子句中有日期。

WITH

MEMBER [Amount LM] as
    (
        [Measures].[Amount],

        ParallelPeriod (
            [Date].[Year - Quarter - Month - Date - Hierarchy].[Year and Month],
            1,
            [Date].[Year - Quarter - Month - Date - Hierarchy].CurrentMember
        )
    )


SELECT 
   {[Amount LM], [Measures].[Amount]} ON  COLUMNS,

[Measure Types].[Name].&[22] --not related to [Measures].[Amount]; Used as a measure switch in the real case but adjusted here for simplicity
-- comment out the next line to fail
* [Date].[Year - Quarter - Month - Date - Hierarchy].[Year and Month] 

ON rows


FROM [Cube]
WHERE [Date].[Year Number].&[2019]
;

工作案例的结果：

                           Amount LM  |  Amount
    Costs  |    Jan 2019  | (null)    |  109600
    Costs  |    Feb 2019  | 109600    |  218300.5
    Costs  |    Mar 2019  | 218300.5  |  392250
    Costs  |    Apr 2019  | 392250    |  206800
    Costs  |    May 2019  | 206800    |  174700
    Costs  |    Jun 2019  | 174700    |  298400
    Costs  |    Jul 2019  | 298400    |  264550
    Costs  |    Aug 2019  | 264550    |  424100
    Costs  |    Sep 2019  | 424100    |  129650
    Costs  |    Oct 2019  | 129650    |  330050
    Costs  |    Nov 2019  | 330050    |  (null)
    Costs  |    Dec 2019  | (null)    |  (null)

没有

* [Date].[Year - Quarter - Month - Date - Hierarchy].[Year and Month]

part, Amount LM ist NULL

          |Amount LM| Amount
    Costs | (null)  | 2548400.5

Answer 1

你的计算没有问题。要了解 Null，您需要了解

ParallelPeriod 的工作原理
UserHierarchy "CurrentMember" 如何工作

当你有

"[Date].[Year - Quarter - Month - Date - Hierarchy].[Year and Month]"

在你的行轴上

"[Date].[Year - Quarter - Month - Date - Hierarchy].CurrentMember"

上面的“.currentmember”表达式return是USER HIERARCHY“[Year - Quarter - Month - Date - Hierarchy]”的当前成员。 PARALLEL PERIOD 函数然后尝试查找关于 LEVEL“[Year and Month]”的表亲成员。

当您从 rows 中删除用户层次结构时，当前成员 returns 2019，它是 LEVEL "YEAR Number" 的成员，因此并行期找不到关于 LEVEL 的表亲“[Year和月]”（因为传递的当前成员高于指定的级别）。要检查用月份成员（并且行上没有日期）替换其中的年份，它将起作用。要解决此问题，您需要提供备用逻辑，以防万一传递了更高级别的成员或其他边缘情况使用下面的脚本，它将 return 100 在任何边缘情况下。

WITH

MEMBER [Amount LM] as
case when [Date].[Year - Quarter - Month - Date - Hierarchy].CurrentMember.level.name <>"Year and Month" then 100
else 
(
    [Measures].[Amount],

    ParallelPeriod (
        [Date].[Year - Quarter - Month - Date - Hierarchy].[Year and Month],
        1,
        [Date].[Year - Quarter - Month - Date - Hierarchy].CurrentMember
    )
)
end

以下是您在 Adventure works 上遇到的问题的示例。我添加了两列来检查 ParallelPeriod 和 .currentmember 是什么 return

WITH
MEMBER [Amount LM] as
(
    [Measures].[Internet Sales Amount],
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember)
)

MEMBER [Amount LM_ParallelPeriodName] as
(
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember).name
)

MEMBER [Amount LM_CalendarCurrentmember] as
(
    [Date].[Calendar].currentmember.name
)

SELECT 
{[Amount LM], [Measures].[Internet Sales Amount],[Amount LM_ParallelPeriodName],[Amount LM_CalendarCurrentmember]} ON  COLUMNS,
[Product].[Category].&[1] * [Date].[Calendar].[Month]
ON rows
from [Adventure Works]
WHERE [Date].[Calendar Year].&[2013]

结果

现在让我们评论

"[Date].[Calendar].[Month]"

WITH
MEMBER [Amount LM] as
(
    [Measures].[Internet Sales Amount],
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember)
)

MEMBER [Amount LM_ParallelPeriodName] as
(
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember).name
)

MEMBER [Amount LM_CalendarCurrentmember] as
(
    [Date].[Calendar].currentmember.name
)

SELECT 
{[Amount LM], [Measures].[Internet Sales Amount],[Amount LM_ParallelPeriodName],[Amount LM_CalendarCurrentmember]} ON  COLUMNS,
[Product].[Category].&[1] --* [Date].[Calendar].[Month]
ON rows
from [Adventure Works]
WHERE [Date].[Calendar Year].&[2013]

结果注意由 ParallelPeriod 编辑的 Null return，现在让我们从 Month 中替换 Year。这使 paralellperiod 能够 return 一些有用的东西

WITH
MEMBER [Amount LM] as
(
    [Measures].[Internet Sales Amount],
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember)
)

MEMBER [Amount LM_ParallelPeriodName] as
(
    ParallelPeriod ([Date].[Calendar].[Month],1,[Date].[Calendar].currentmember).name
)

MEMBER [Amount LM_CalendarCurrentmember] as
(
    [Date].[Calendar].currentmember.name
)

SELECT 
{[Amount LM], [Measures].[Internet Sales Amount],[Amount LM_ParallelPeriodName],[Amount LM_CalendarCurrentmember]} ON  COLUMNS,
[Product].[Category].&[1] * [Date].[Calendar].[Month]
ON rows
from [Adventure Works]
WHERE [Date].[Month Name].[September 2013]

结果

当时间不在轴上时出现 ParallelPeriod 问题

ParallelPeriod issues when time is not on axis

ssas

mdx

olap