Tag Archives: Excel 2013

DISCOVER_COMMANDS DMV – Improve Drillthrough & Learn DAX Query

In the past I’ve demonstrated a few examples of using DAX Query in PowerPivot workbooks, this “create a Date Dim” for example.

The ability to produce tables rather than just pivots can be very useful; not just for ETL-like activities like the above mentioned Date Dim, but also for testing and development; and for producing pivot friendly flattened tables for consumption by other other data vsiualisation toolsets.

I’ve been asked a few times what’s the best way to learn DAX Query? Well, in most respects, it’s the same as the standard DAX used to build measures and calculated columns, so just keep practicing that measure building!

But, another interesting way, is to see the DAX auto-created by a tool that, I suspect, was the original use-case for tabular DAX i.e. PowerView.

PowerView comes with Excel 2013 (at least those versions that also pack the PowerPivot add-in) so you no longer require a SharePoint farm to try it out.

(One thing to note if you’re running a 64bit version of Excel 2013, you’ll need to source a 64 bit version of Sliverlight; the 32bit download that you’ll be prompted to install via your (32bit) browser will not work.)

Here’s a good introduction to  report building in PowerView by MSBI Academy.

To see the DAX generated by PowerView (and indeed the MDX generated by the workbook’s pivotables) use the DMV view DISCOVER_COMMANDS.

For Excel 2010 you would have used my trick to fire DMV views, but this no longer works in 2013. So, instead, you can use this trick to execute any DAX, MDX or DMV.

Note: you’ll need a true external connection (a workbook table will not enable the Edit DAX option). Also, the table’s connection points at the model, so be careful with the Refresh command (i.e it’ll cause the table to refresh). It’s a little bit more complex, it depends on the nature of the DAX; the engine uses a dependency graph it seems (which is good, shows this feature is fully integrated). If your DAX mentions a column on a table, then that table will be refreshed.

The Edit Dax action uses a…

Connections(“ModelConnection_<<whatever>>”).Refresh

…which is obviously only between workbook and model, so doesn’t cause this external refresh.

You may also notice that sometimes the sequence of columns returned is different from expected, I usually find re-issuing the DAX command fixes this.

Because of the awkwardness of the above hack(s) when I don’t need this dependency stuff I usually revert to my HAMMER micro-ETL utility to do any DAX, MDX or DMV queries via the HAMMER(“PPCONECTION”, <<my command>>, “ADO”) command set.

You could also write your own ADO code, latching on to the ActiveWorkbook.Model.DataModelConnection.ModelConnection.ADOConnection connection object.

Not only can you see examples of DAX Query construction using the above methods, but you can also run/modify the extracted commands using the same.

Another very useful use of DISCOVER_COMMANDS is to pick-up the MDX DRILLTHROUGH command issued when a Show Details is applied to a pivottable cell.

You can then, for example, change the MAXROWS returned (something that disappeared in 2013, only other method is to open the workbook ZIP source and modify the Connection’s XML).

But even better, you can pick a different set of columns to return. This is so useful, as normally the default DRILLTHOUGH usually doesn’t bring back useful columns such as the row’s unique ID!

See here for a workbook containing examples of the above.

To use the HAMMER commands you’ll need to manually open the xll (make sure to pick the correct bitness).

To enable HAMMER’s full functionality (namely any command, such as HAMMERtoFit, that uses a background thread) you’ll need to close and reopen Excel. This is something new in Excel 2013, probably related to ensuring that an internet-delivered workbook doesn’t  use something like a background thread to do something nasty before it has been “trusted”. Well that’s my theory anyway, and I’m sticking to it. Anybody else seen similar?

UPDATE: Another method to have fun with DAX Query expressions is Dax Studio, which now supports Excel 2013! http://geekswithblogs.net/darrengosbell/archive/2013/05/04/new-release—dax-studio-1.2-with-excel-2013-support.aspx

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DAX’s back – Create DAX Measures in Excel 2013 without PowerPivot Add-in

I mentioned in my last post that it was possible to create DAX measures (and indeed Calculated Columns, KPIs etc.) without using the PowerPivot add-in but instead using AMO to do so. The facility has always existed in HAMMER but only as a hidden option that I often used to iterate quickly through a set of measure variations (or load standard sets) during model development; but I wasn’t 100% convinced it was worth the effort to make it more production quality in order to add it to HAMMER’s public interface. But, with the extraordinary removal of PowerPivot add-in as an option for all retail versions and all O365 SME versions of Office 2013, I decided to revisit the code and make it available as a new HAMMER command “PPMAKEMEASURES”.

This zip file contains an example of an Excel 2013 workbook (drawing data from a Northwind oData public feed) with DAX measures created by HAMMER rather than via the PP add-in.

The HAMMER formula and associated “list-of-measures” table can be found within.To use the formula on this, or another workbook, you need to activate HAMMER.xll (or HAMMER-64.xll, if using Excel 64bit) by either opening like a normal workbook (will not be installed as a permanent add-in) or put it in your add-ins folder and register as per a normal XLL (you can also use VBA’s registerDll functionality for automatic only-this-instance registering).

The first time you apply this method of DAX measure creation to a workbook, you should save, close & re-open the workbook; otherwise, you run the risk of the created measures being overwritten if you subsequently create an implicit measure (by moving a field to the Values section of a pivot table). If saved, this will no longer be a problem. If you use this in Excel 2010 you’ll always need to save,close & reopen in order to see the new measures. (Also, in 2010 you’ll need to precede any PP commands with the PPCONNECTION command e.g. =HAMMER(“PPCONNECTION”,Table2[#All],”PPMAKEMEASURES”) UPDATE: It appears you also need the PPCONNECTION in 2013 although I don’t appear to need it in my O365 version!).

To get a list of DAX Measures within a workbook use the PPLISTMEASURES command (e.g. =HAMMERToRange(“PPCONNECTION”,”PPLISTMEASURES,”Sheet2!A1″) will paste a table to Sheet2 starting at cell A1). The table will be in the format required by the PPMAKEMEASURES command and is intended as a quick way of transferring measures from one workbook (even if 2010) to another. (Note: this will list both implicit and explicit measures, best avoid creating implicit measures using this method!)

The table is position based (i.e. heading values not important, just as long as there is a heading line); columns represent – Table Name, Measure Name, DAX, Format and Visible. If the 3rd column, i.e. the DAX expression, is blank, the measure will be deleted, otherwise, any existing measures will be deleted and replaced with the new definitions.

This has only been tested against  O365 versiond of Excel 2013, retail versions may be different. I needed to hard-code the location of the AMO & ADOMD dlls (unlike 2010 they’re no longer in GAC and are not on a PATH – well, likely they are, but only in the virtual file system now used by Office).

The location for the AMO library for 32bit O365 Home Premium is  “C:/Program Files/Microsoft Office 15/root/vfs/ProgramFilesCommonX86/Microsoft Shared/OFFICE15/DataModel/Microsoft.Excel.AMO.dll” let me know if your setup is different. (UPDATE: As Marco discovered, enterprise and most likely retail versions do not use VFS, I‘ll post a fix to this tomorrow). UPDATE: PATH issues with none O365 versions should now be fixed.

If you’re a SME or sole-trader and you intend to use PowerPivot extensively you really need to purchase (as I have) the O365 Professional Pro subscription for your “datasmiths”. The rest of your crew can use Retail or O365 offerings (as they can still “consume” DAX powered models). But if, for some reason, you can’t or won’t purchase ProPlus, or you just want to take advantage of the fast build-redesign-build cycle offered by PPMAKEMEASURES, then hopefully, this will be of use.

Oh, and Happy St. Patrick’s day!

Building an Excel 2013 Percentile dashboard without PowerPivot or a PivotTable

At the end of my Playing DAX Percentiles on the mean (or is that median) Streets of Ireland post I suggested that plain old Excel (POE) might be a preferable alternative for this particular problem rather than using PowerPivot. In fact, for many Excel users, PowerPivot will only be an option when using a PC hosted client-side workbook. Excel 2013 will allow workbooks to be published on the web and also be accessible via native apps on Windows 8 tablets (and eventually iPad & Android native apps if rumours are to be believed).

But, PowerPivot (aka Data Model) functionality will only be available to those with an enterprise-class SharePoint licence (for web publishing) and not at all for native-app-deployed workbooks. So, knowing how to use POE to construct dashboards continues to be a skill worth having.

But how to construct a responsive percentile calculating dashboard sans PowerPivot?

You might think, no problem, I’ll use a traditional PivotTable; alas, like PowerPivot, it lacks the ability to calculate percentiles as standard; but, unlike PowerPivot, offers no method of constructing a DIY measure to do so!

Next up, you might look at the SUMIFS family of “pivot” functions, but they too are limited to the usual aggregates; and SUBTOTAL is likewise limited to the usual suspects.

Luckily, via the (black!) magic of array formulas there is a way.

In fact, the “trick” below when shown to me by a “civilian” datasmith many years ago, convinced me that I should perhaps invest some time getting my head around this powerful “array formula magic”.

If you’re already comfortable with array formulas and are wondering if DAX is too complex to master, don’t worry, you’ll have little trouble mastering DAX. Likewise, if you’re a DAX whiz, you should check out array formulas.

Basing the dashboard on the Property Register converted to an Excel Table (a 2007+ feature that many are still unaware of) enables the use of  Slicer selectors in Excel 2013 to quickly give a dashboard feel. It’s still possible to use the Excel Table filters directly on the table (the built-in date and text filters are particularly useful).

Also, in Excel 2013, a chart can be directly “animated” by a range/table without the need for a PivotTable cache, again making the building of “PivotTableLess” dashboards easier.

A lot of this can also be accomplished in sub 2013 versions of Excel (including, most importantly, the array formula “trick”) but Excel 2013 just makes it all so much easier and, of course, the ability for every user (from Home to Pro) to save and/or publish workbooks via “the cloud” is a major advance (big thanks to Google Docs, without you this might never have happened 😉 ).

UPDATE:

See David Hager comment, there’s a new 2010+ AGGREGATE function which has many more options than SUBTOTAL, including Percentiles, so you can ignore the trick below if using 2010/2013. The trick would still be useful to supply an array to a bespoke formula (I used it first to calculate a particular type of weighted average) or to functions such as IRR or XIRR, so still useful to know even in modern versions of Excel.

UPDATE:

See the TheDataSpecialist’s comment for a even better modern make-over of the SUBTOTAL(3, trick.

Below is the formula to calculate a median using only “visible” rows within a filtered table/range. Note: it’s an array formula, so it must be entered using the CTRL SHIFT and ENTER keys.

{=MEDIAN(IF(SUBTOTAL(3,OFFSET(Prices[Price],ROW(Prices[Price])-MIN(ROW(Prices[Price])),,1)),Prices[Price],””))}

I used this Excel formula beautifier to make it more readable.


MEDIAN
(
    IF
    (
        SUBTOTAL
        (
            3,
            OFFSET
            (
                Prices[Price],
                ROW
                (
                    Prices[Price]
                ) -
                MIN
                (
                    ROW
                    (
                        Prices[Price]
                    )
                ),
                 ,
                1
            )
        ),
        Prices[Price],
        ""
    )
)

This logic behind this is explained here, but essentially, the OFFSET() portion returns either a filtered range of one or zero rows (counted by the SUBTOTAL(3,…) part). if one ,it’s a visible row, if zero, it’s not visible, so ignore.

If this makes no sense (it didn’t to me the 1st time I saw it), then don’t worry, just make a note of it and use the trick in blind faith :).

You can see this in action in “the cloud” here as a read-only “Excel Web App”, (you can also download the workbook to see its internals).

If you’re reading this sometime in the future the above link may not work as it’s published using a beta version of Office 2103, here’s a direct link to the Excel 2013 workbook.

And if you haven’t yet installed Excel 2013, here’s a cut-down 2007/2010 version.