[MDX学习笔记之一]MDX中一些常见的计算
本文来源于《MDX Solutions with Microsoft SQL.Server Analysis Services 2005 and Hyperion Essbase 2nd Edition》一书的内容，主要介绍了一些经常编写的MDX语句的写法。以下MDX语句可以在SSAS的示例库：Adventure Works中运行。
例子模型
以下的MDX中用到的Hierarchy如下：
![[MDX学习笔记之一]MDX中一些常见的计算_第1张图片](http://img.e-com-net.com/image/product/246cfc6e00ad4bdbad660262058b8a45.png) |
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百分比
1）某个子项占总体的百分比。比如：每种Product的销售额占所有Product销售额的百分比。
WITH
MEMBER
[
Measures
]
.
[
Sale Amount Ratio
]
AS
' [Measures].[Internet Sales Amount]/([Measures].[Internet Sales Amount], [Product].[Product Categories].[All]) ' , FORMAT_STRING = ' 0.00% '
SELECT
{ [ Measures ] . [ Internet Sales Amount ] , [ Measures ] . [ Sale Amount Ratio ] } ON 0 ,
NON EMPTY [ Product ] . [ Product Categories ] . [ Product Name ] .Members ON 1
FROM [ Adventure Works ]
' [Measures].[Internet Sales Amount]/([Measures].[Internet Sales Amount], [Product].[Product Categories].[All]) ' , FORMAT_STRING = ' 0.00% '
SELECT
{ [ Measures ] . [ Internet Sales Amount ] , [ Measures ] . [ Sale Amount Ratio ] } ON 0 ,
NON EMPTY [ Product ] . [ Product Categories ] . [ Product Name ] .Members ON 1
FROM [ Adventure Works ]
2）某个子项占其父项的百分比。比如：每种Product的销售额占其所属的SubCategory销售额的百分比。
WITH
MEMBER
[
Measures
]
.
[
Sale Amount Ratio
]
AS
'
[Measures].[Internet Sales Amount]/([Measures].[Internet Sales Amount], [Product].[Product Categories].CurrentMember.Parent)
'
, FORMAT_STRING
=
'
0.00%
'
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
,
[
Measures
]
.
[
Sale Amount Ratio
]
}
ON
0
,NON EMPTY CROSSJOIN(
[
Product
]
.
[
Subcategory
]
.
[
Subcategory
]
.Members, [ Product ] . [ Product Categories ] . [ Product Name ] .Members) ON 1
FROM
[
Adventure Works
]
3）某个子项占其祖先的百分比。比如：每种Product的销售额占其所属的Category销售额的百分比。
WITH
MEMBER
[
Measures
]
.
[
Sale Amount Ratio
]
AS
'
[Measures].[Internet Sales Amount]/([Measures].[Internet Sales Amount], ANCESTOR([Product].[Product Categories].CurrentMember, [Product].[Product Categories].[Category]))
'
, FORMAT_STRING
=
'
0.00%
'
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
,
[
Measures
]
.
[
Sale Amount Ratio
]
}
ON
0
,NON EMPTY CROSSJOIN(
[
Product
]
.
[
Category
]
.
[
Category
]
.Members,
[
Product
]
.
[
Product Categories
]
.
[
Product Name
]
.Members)
ON
1
FROM
[
Adventure Works
]
分配、分摊数量
1）根据一个Measure值来分配数量。比如：按照每种Product占总体的销售额多少来分摊成本。
WITH
MEMBER
[
Measures
]
.
[
Product Cost
]
AS
'
([Measures].[Internet Total Product Cost], [Product].[Product Categories].[All])*[Measures].[Internet Sales Amount]/([Measures].[Internet Sales Amount], [Product].[Product Categories].[All])
'
, FORMAT_STRING
=
'
0.00
'
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
,
[
Measures
]
.
[
Product Cost
]
}
ON
0
,NON EMPTY
[
Product
]
.
[
Product Categories
]
.
[
Product Name
]
.Members
ON
1
FROM
[
Adventure Works
]
2）根据一个Hierarchy来分配数量。比如：在Product Hierarchy中计算每种Category的成本的时候，可以根据每种Category下有多少个产品来进行分配。
WITH
MEMBER
[
Measures
]
.
[
Product Cost
]
AS
'
([Measures].[Internet Total Product Cost], [Product].[Product Categories].[All])/Count( Descendants ( [Product].[Product Categories].CurrentMember, [Product].[Product Categories].[Product Name], SELF ), INCLUDEEMPTY)
'
, FORMAT_STRING
=
'
0.00
'
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
,
[
Measures
]
.
[
Product Cost
]
}
ON
0
,NON EMPTY
[
Product
]
.
[
Product Categories
]
.
[
Category
]
.Members
ON
1
FROM
[
Adventure Works
]
平均值
1）简单平均值。比如：计算一个月中每天平均的销售额是多少。
WITH
MEMBER Measures.
[
Avg Gross Profit Margin
]
AS
[
Measures
]
.
[
Internet Sales Amount
]
/
COUNT
(Descendants(
[
Ship Date
]
.
[
Fiscal
]
.CurrentMember,
[
Ship Date
]
.
[
Fiscal
]
.
[
Date
]
), INCLUDEEMPTY)
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
, Measures.
[
Avg Gross Profit Margin
]
}
ON
COLUMNS,
[
Ship Date
]
.
[
Fiscal
]
.
[
month
]
.Members
ON
ROWS
FROM
[
Adventure Works
]
2）加权平均值。没有想到好的例子。
基于时间的计算
1）同比和环比。比如：今年每月的销售额和去年同期相比的变化
参见前两天写的Blog : http://www.cnblogs.com/microsheen/archive/2006/10/28/542818.html，这里要补充的是，在同比MDX中，采用COUSIN或ParallelPeriod都可以，但是采用ParallelPeriod更好一些。
2）累计到当前的统计。比如：得到一年中每一个月的累计销售额。
WITH
MEMBER Measures.
[
Additive Internet Sales Amount
]
AS
SUM
( PeriodsToDate(
[
Ship Date
]
.
[
Fiscal
]
.
[
Fiscal Year
]
,
[
Ship Date
]
.
[
Fiscal
]
.CurrentMember),
[
Measures
]
.
[
Internet Sales Amount
]
)
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
, Measures.
[
Additive Internet Sales Amount
]
}
ON
COLUMNS,
[
Ship Date
]
.
[
Fiscal
]
.
[
month
]
.Members
ON
ROWS
FROM
[
Adventure Works
]
3）移动平均值。比如：计算一种Category过去三个月的平均销售额合计。
WITH
MEMBER Measures.
[
Average Internet Sales Amount
]
AS
AVG
(LastPeriods(
3
,
[
Date
]
.
[
Calendar
]
.CurrentMember),
[
Measures
]
.
[
Internet Sales Amount
]
)
SELECT
{
[
Measures
]
.
[
Internet Sales Amount
]
, Measures.
[
Average Internet Sales Amount
]
}
ON
COLUMNS, NON EMPTY (
[
Product
]
.
[
Product Categories
]
.
[
Category
]
.Members, DESCENDANTS(
[
Date
]
.
[
Calendar
]
.
[
Calendar Year
]
.
&
[
2002
]
,
[
Date
]
.
[
Calendar
]
.
[
Month
]
, SELF) )
ON
ROWS
FROM
[
Adventure Works
]
总结
MDX的表现力非常强大，以上的一些内容希望起到抛砖引玉的作用。