Tag Archives: Aggregate function

Errors, MDX, SSAS

MDX Aggregate Functions Can Not Be Used on Calculated Members in the Measures Dimension

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If you’ve ever tried to use the Aggregate function on a calculated measure, you’ve seen the following error:

Aggregate functions error

This is a problem if you’re trying to calculate something like Year To Date for a calculated measure. Take the following MDX query (which I understand doesn’t make sense and isn’t something you’d do in a real world situation, but just go with it for the sake of the example), which can be run against the Adventure Works cube, for example:

WITH MEMBER [Measures].[YTD Average Price] AS Aggregate ( PeriodsToDate( [Date].[Calendar].[Calendar Year], [Date].[Calendar].CurrentMember) , [Measures].[Internet Average Unit Price] ) Select [Measures].[YTD Average Price] on0, [Date].[Calendar].[Date] on1 From [Adventure Works] Where [Date].[Calendar Year].&[2003]

 

If you execute this query, it will complete successfully with #Error as the results. You have a couple different options. First, you could replace the Aggregate function with the Sum function. If you are unable to use the Sum function, then you’ll have to  adjust the way you calculate Year to Date Average Price. We’ll have to break this up into a couple different calculations.

WITH MEMBER [Measures].[YTD Unit Price] AS Aggregate ( PeriodsToDate( [Date].[Calendar].[Calendar Year], [Date].[Calendar].CurrentMember) , [Measures].[Internet Unit Price] ) MEMBER [Measures].[YTD Transaction Count] AS Aggregate ( PeriodsToDate( [Date].[Calendar].[Calendar Year], [Date].[Calendar].CurrentMember) , [Measures].[Internet Transaction Count] ) MEMBER [Measures].[YTD Average Price] AS [Measures].[YTD Unit Price]/[Measures].[YTD Transaction Count], format=“Currency“Select [Measures].[YTD Average Price] on0, [Date].[Calendar].[Date] on1 From [Adventure Works] Where [Date].[Calendar Year].&[2003]

 

Doing our calculation this way, we are able to work around our inability to use the Aggregate function on a calculated member. I hope this gives someone an idea of how they can work around this annoying issue.