Random Procrastination

Darren Gosbell [MVP]

Power BI – Using Field Parameters in Paginated Reports

Field Parameters are a relatively new feature in Power BI which are still in preview and they add a lot of flexibility to an interactive reporting solution, but can they be used in paginated reports?

The short answer is yes, but the experience is not as simple as it is in Power BI Desktop. The reason for this is that Power BI Desktop does not just pass field parameters as filters to other visuals, they actually change the way the underlying DAX queries are generated.

The following example of an Adventure Works based report with a field parameter that allows the user to choose between showing either the Total Sales measure or the Total Quantity measure.

If we use the Performance Analyzer in Power BI Desktop to capture all the queries for this page we find 2 sets of queries.

The first one for the slicer looks as follows and just gets a list of values from our Field parameter table:

// DAX Query
DEFINE
  VAR __DS0Core = 
    SUMMARIZE(
      VALUES('Measures Parameter'),
      'Measures Parameter'[Measures Parameter Fields],
      'Measures Parameter'[Measures Parameter Order],
      'Measures Parameter'[Measures Parameter]
    )

  VAR __DS0PrimaryWindowed = 
    TOPN(
      101,
      __DS0Core,
      'Measures Parameter'[Measures Parameter Order],
      1,
      'Measures Parameter'[Measures Parameter],
      1,
      'Measures Parameter'[Measures Parameter Fields],
      1
    )

EVALUATE
  __DS0PrimaryWindowed

ORDER BY
  'Measures Parameter'[Measures Parameter Order],
  'Measures Parameter'[Measures Parameter],
  'Measures Parameter'[Measures Parameter Fields]

To start integrating our Field Parameters into our paginated report we can create a new paginated report using Power BI Report Builder and we can copy and paste this query into a new dataset. I’ve called this dataset “MeasureParameter” in the screenshot below:

We can then create a new report Parameter linked to this dataset. I’ve called my parameter “MeasureName” and I’ve linked up the available values as follows:

Note that I’m using the field for the Value property which returns the full DAX reference for the measure (eg. ‘Sales'[Total Sales]) and I’m using the display name of the measure for the label field (eg. “Total Sales”)

This will generate a parameter like the following when the paginated report is run to allow the user to select which measure to use:

If we then look at the second set of queries in the Performance Analyzer, we can see that the there are actually 2 queries.

  1. Gets the data for the chart and this query is dynamically generated
  2. Gets the name of the currently selected Field Parameter which is used to populate the chart title and axis labels

We can ignore query 2 as we already have the information about the field parameters in our MeasureParameters dataset, but how do we dynamically generate our query in the same way that Power BI does?

The answer to this is using expressions. Paginated Reports are extremely powerful in this regard and almost all of the properties of the objects in a report can set using expressions – even the query text and that is what we are going to do in this case.

If we look at the text of the first query we captured from Performance Analyzer, it looks as follows:

Where you can see on lines 4 and 7 that the ‘Sales'[Total Sales] measure is referenced (which I’ve highlighted in yellow. And on lines 7, 10 and 16 that this is given a name of [Total_Sales] in the output from the query. The [Total_Sales] is just a column name in the results of the query and we could leave it as end users of our report will not see this reference, but I prefer to make it clear that this is may not always be the Sales measure, so I renamed it to [Measure_Value]

Then I created a new Dataset called “Dataset1” and pasted the above static query in and clicked “OK” this saves our dataset and generates the field mappings for us. (you can manually create the field mappings from the resultset to the paginated dataset, but I find this method of starting with a static query easier)

Then to make this query dynamic I clicked the “fx” button next to the Query property to open the expression editor.

I then made the following changes to the query text:

  1. First, I started the expression with an = sign, this tells the report engine that this value needs to be evaluated as an expression. Then I added a double quote character as this is the start of a string expression.
  2. Then I added a closing double quote character at the end of the query.
  3. I then went through the rest of the query and doubled up any existing double quote characters to escape them.
  4. Finally, I inserted some concatenation expressions to add in the Value property from our MeasureName parameter which we added earlier using the Parameters!MeasureName.Value reference.
configuring the dynamic query

So, we now have a dynamic query which will inject the measure to be used based on the parameter chosen by the user at run time.

To test this we can put a simple table on our report canvas and link up the Color and Measure value fields

Configuring the column references for the table visual

This gives us a table which looks like the following

The design time report layout

And when we run it and choose a measure from the parameter we get the data we expect, but we cannot easily tell from the report which measure was selected by the user since the column header just says “ID Measure Value”. So if this report was exported to a PDF or sent as part of an emails subscription it might be hard to tell which measure was selected.

The basic report with a dynamic query

To fix this we can right click on the “ID Measure Value” header and turn this column header into an expression instead of being static text.

Editing the measure expression for the column header

Then we can use an expression like the following to use the label of the selected parameter value as column header

=Parameters!MeasureName.Label

If we also bold the column headers, now when we run our report, we get an experience almost identical to that in Power BI Desktop and our table now shows which measure was selected in the header for the measure column.

Final Report

This same technique of using an expression-based query could be adapted to work with field parameters that reference columns instead of measures. The expression for the query would just need to be adjusted differently, but I will leave this as an exercise for the reader.

Power BI Report Server – fixing “Can’t upload this report”

A little while ago at my previous job we had a new user report an issue where they could not upload a Power BI Report to our Report Server and I found a simple fix which I thought was worth sharing.

In this case they were getting the error that the report was created with a recent version of Power BI Desktop that is not yet supported by this server.

So, how did this happen…

When you are running Power BI Report Server it is really important that your report authors use the Report Server version of Power BI Desktop that matches the release of your Server.

If you are not already aware there are actually 3 different distributions of Power BI Desktop

  • The Windows Store version
  • The Standalone installer version
  • The Power BI Report Server version

If you are running an on-prem Power BI Report Server, it is vital that you use the Report Server version of Power BI Desktop. Failing do so can mean that you may spend hours building a report that will not run on the server.

If you are not sure where to get this the Report Server Portal has a download link in the top right corner with a link (provided you are running one of the supported releases of Report Server, once the server goes out of support the downloads for Desktop are removed)

On my machine I have both the Microsoft Store version of desktop and the Report Server version. You can tell the difference because the Report Server version has a little black “RS” on the logo and the application title always includes the release month.

What had happened with this user was that someone had sent them a pbix file to work on. Being new to the organization they just downloaded the Microsoft Store version of Power BI Desktop, did their updates to the file and then tried to upload it to Power BI Report Server and this is when they got this error.

The problem is that now the file will not open in the Report Server version of Power BI Desktop since the file format has been updated to work with the newer version of Desktop from the Store.

Fix 1 – Manually rebuild the report

If your report is small and you realize this early, maybe just re-creating the report is an option, but often you do not realise this mistake until you have invested a significant amount of time in your report.

Fix 2 – Copy/Paste

One way to “fix” this is to run both the “Store” version of Desktop and the “Report Server” version of Desktop. Then open the file in the “Store” version of Desktop and manually copy the Power Query text from the Advanced editor, then copy measures and any calculated columns and tables, then copy visuals from one report to the other. As long as you have not used any new functionality that does not exist in Report Server this can work fine and is less work than a full manual re-build.

Fix 3 – Create a template file

This is the simplest option if it works.

All I did was to open the report in the “Store” version, did a “save as” and changed the type to a Power BI Template file. Then the user was able to open the resulting pbit file in the “Report Server” version of Desktop. Then I could refresh the data and upload it to Report Server.

This probably only works if you have not used functionality that only exists in the cloud service, but if you are using the lastest release of Report Server this number of things in this category should be relatively small. If you can identify any items like this, you may be able to remove them from your report before creating the template file.

DAX Studio v3.0.1 Released

I’ve just pushed out an update to DAX Studio with a number of fixes and a few small updates. You can download it now from https://daxstudio.org

Updates

  • Added query information button to traces
    (This captures the actual query text and any parameter values plus the ActivityID)
  • Updated Query History icons
  • #949 Exposed Theme/Mode setting in Options
  • Added MPARAMETER keyword to syntax highlighting

Fixes

  • Fixed #891 Error exporting to static Excel file
  • Fixed #889 crash when dragging trace windows
  • Fixed #886 incorrect link to tutorial in Getting Started dialog
  • Fixed #894 Define and Expand sometimes producing incorrect output
  • Fixed #924 username blank in All Queries trace
  • Fixed #930 increased default code completion window width
  • Fixed #931 automatically select all text in find/replace dialog
  • Fixed #906 improved waterfall layout in Server Timings
  • Fixed setting focus in the editor when changing tabs
  • Fixed file icon registration
  • Improved error handling around shutdown operations
  • Added extra hotkey validation rules
  • Fixed #916 added retry logic to all clipboard operations
  • Improved Power BI filename detection for non-English cultures
  • Removed unused dependencies and reduced installer/portable file size

DAX Studio v3 released!

I know it’s been a while since I’ve released an update to DAX Studio. But I’m happy to announce that version 3.0 is now available with a major update to the User Interface including the option for a Dark theme. You can download it from https://daxstudio.org (which has also had a major update and can be viewed in Dark mode) and you can read about what’s new in this release here: v3 Release | DAX Studio

Power BI Report Server – an unexpected error occurred (Nov 2021)

Earlier this week we started getting reports of the following error on our production Power BI Report Server (PBIRS) instance for any reports that were using a live connection back to one of our Analysis Services models.

All it basically said was “an unexpected error occurred. Please try again later”. And if you looked at the details it showed the message above saying that “We could not connect to the Analysis Services server”.

Some other fun facts about this issue are:

  • It was not affecting all users (at least in our environment)
  • There had been no recent updates or configuration changes on PBIRS, SQL or SSAS
  • The same issue appeared to be affecting our test environment but not our development environment.
  • It was happening for both pbix and paginated reports
  • It was affecting reports that sourced data from SQL Server as well as SSAS
  • When running a profiler trace against SSAS listening for the session events I could see some sessions with usernames and others where the user was listed as “ANONYMOUS USER”

Putting all of the above evidence together point to some sort of Kerberos issue. In our environment our SQL and SSAS instances are on different servers to our PBIRS instance we had to configure Kerberos with constrained delegation to allow for the user credentials to flow from client > to PBIRS > to SSAS.

Kerberos can be a little fiddly to setup initially, but once it’s configured I’ve never had an issue with it until the one this week. When we initially configured Kerberos I had distilled the generic instructions from the Microsoft documentation down into a series of specific steps for our production environment listing the specific setspn commands that needed to be run and how the constrained delegation settings needed to be configured and saved these in a document. This made it very easy to cross check that all these configurations were still correct.

At this point we knew that the Kerberos configuration appeared to be unchanged, but we still had an issue where it worked for some users and not for others.

So the next thing I started doing was to get some of our users to run the klist command from a command prompt. This command lists all the Kerberos tickets that are cached on the current machine. This lead us to find a pattern where everyone that was getting the error were getting their kerberos tickets from a specific list of domain controllers while people that did not have the issue were getting theirs from a different list of domain controllers. Our IT admins then noticed that all the failing servers were in a group which had had security patches applied earlier that day.

The specific patch that had been applied was KB5007206 and after raising a support ticket with Microsoft they were able to point us to the following hotfix (KB5008602) for this update which fixed an issue when you were using Kerberos authentication with constrained delegation and protocol transition (which is exactly how Kerberos needs to be configured when using PBIRS or SSRS or SSRS in Sharepoint integrated mode for people with on-prem Sharepoint environments).

Hopefully this post will help anyone else that runs into this issue.

DAX Studio 2.17.2 released

DAX Studio 2.17.2 has just been released and the following is a run down of the new features and fixes that you will find in this release.

Apologies to anyone who attempted to download the 2.17.0 release – there was an update to the code signing tool and it failed to correctly sign the installer. The automated build has now been fixed so that it correctly signs the installer again.

New Features

Added Parameter support to Query Builder filters

The Query Builder now supports parameters. Typing an @ as the first character in a query builder filter value will switch the value into parameter mode and the following text will be treated as the parameter name. (typing @ a second time or clicking on the purple @ button will toggle the parameter back to the standard value mode)

When you run the query builder where a filter has a parameter you will be prompted for the parameter value just as if you had typed out a query that included a parameter reference. This allows you to build a query with parameters that can be pasted into a paginated report or any other tool that supports DAX parameters.

Running Query Builder with a filter parameter

Removing <pii> tags from xmSQL in Server Timings to improve readability

Power BI and AzureAS have added <pii> tags around some of the text in the query events that DAX Studio captures as part of the Server Timings. These tags allow Microsoft to strip out information that could potentially be personally identifiable when writing them to centralized logs. But because DAX Studio does not send any of this information off your machine and because this information also includes important contextual information for troubleshooting and performance tuning we are just removing these tags to reduce the noise and improve readability.

Fixing accuracy of Server Timings for queries with Batch events

Prior to this update Storage Engine batch events timings were not being added to the SE duration figures. For a lot of models this difference is insignificant, but for large queries against large models this can result in an incorrect inflation of the FE duration. Keep an eye on the posts from Marco and Alberto at sqlbi.com as they are working on an in-depth video to explain this improvement to the Server Timings.

Query Builder queries are now captured in the query history

Prior to this update the Query History pane was only capturing the text of queries that had been typed into the query editor. Now the Query History pane captures any query that was executed regardless if it was from the edit window or from the Query Builder.

There is now an icon next to each query history row indicating where it was captured from and if you double click on a query that was originally run in the Query Builder it will be restored back into the Query Builder window

The /f parameter can now open vpax files

Now when you run DAX Studio from the command prompt the /f parameter will open either .dax or .vpax files.

Added extra information to the error message when the XMLA endpoint is not correctly enabled

If the Power BI XMLA endpoint is not properly enabled the Microsoft ADOMD provider returns a very generic error message making it hard to know what has gone wrong. DAX Studio now adds some extra text after the Microsoft error if you are attempting to connect to an XMLA endpoint and hit this generic WebException error to suggest you check the XMLA endpoint settings in your tenant.

Improved caching of measure expressions

Prior to this update features that required access to the text of the multiple measure expression such as the “Define All Measures” feature would request the expression text one at a time, now all of the measure expressions are retrieved in a single request.

Fixes

  • Fixed #703 preventing a crash when entering a proxy password
  • Fixed #715 added DOUBLE data type to intellisense and syntax highlighting
  • Fixed #740 export to Excel failed on some machines
  • Fixed #755 saving parameters to XML was not correctly encoding special characters
  • Fixed #750 would crash on startup if the WMI information on the machine was corrupt
  • Fixed download link in Help – About screen

DAX Studio v2.16.2 Released

DAX Studio v2.16.2 has just been released and is available at daxstudio.org. It includes the following fixes and improvements. The first one being particularly important:

Traces fail to start with a timeout error

Fixed issue #664 – A small refactoring of the trace engine for some future work has accidentally resulted in the engine not being able to detect if a trace has been started or not, resulting in timeout errors. This appears to affect most scenarios apart from one or two edge cases. Unfortunately it was one of those edge cases that was used when testing that the previous code change had not broken anything. The 2.16.2 code base has been tested against all the different engine types PowerPivot, Power BI Desktop, Power BI Desktop as an External Tool, a local SSAS Instance, a remote SSAS Instance, Power BI Premium XMLA Endpoints and Azure Analysis Services

Showing View Metrics Last Refreshed and Analysis Date in the local timezone

Fixed issue #663 – Previously the Last Data Refresh and Date of Analysis were both displayed in UTC in the Summary tab of the View Metrics pane. Internally the dates are still stored in the vpax file in UTC so that that if you send the vpax file to someone in a different timezone the times will n

When saving a file with the Query Builder open custom measure names were not saved

Fixed issue #659 – if you save a file with the query builder open which has custom measures that were created within the query builder then the name of those custom measures was not saving properly prior to this fix.

Debug commas not handling lines with indented comments correctly

Fixed issue #663 – the new debug commas preview feature was not correctly positioning the commas if one of the lines of the query had an indented comment. This issue and a few other ones around different comment placements have been fixed.

View Metrics – Last Refreshed date was incorrectly adjusting from UTC time

Fixed issue #670 – The Last Refreshed Datetime in the View Metrics summary page was incorrectly getting the timezone offset applied twice when calculating the UTC time. This resulted in the time being moved too far forward if your local timezone is behind UTC or too far back if your local timezone is ahead of UTC.

DAX Studio v2.16.1 Released

This update to DAX Studio includes all the new features introduced in 2.16.0 but includes the following bug fixes:

  • #657 Unable to open a new query tab either with a new connection or with a copied connection
  • #658 passing the database name on the command line
  • #647 hidden objects not hidden correctly when show hidden objects option was turned off (this was partially fixed in 2.16.0 but should work in all scenarios now)

Learning to write queries in DAX – Demo Script from DataANZ 2021

If you were in my recent session at the DataANZ 2021 conference I mentioned that I would make a copy of the queries I created during that session so here they are!

In my demos I used the Adventure Works 2020 pbix file from here https://aka.ms/dax-docs-samples

And I added the following simple measure to the Sales table:

Total Sales = SUM( Sales[Sales Amount])

You can download the script of the demo queries from my OneDrive

DAX Studio 2.16 Release

The latest release of DAX Studio is now available with the following new features and fixes.

New Features

Added Sponsor page to daxstudio.org

We are now able to accept sponsorship via Github Sponsors. If you would like to make a financial donation to support the continued development of DAX Studio you can now sponsor the project at https://github.com/sponsors/DaxStudio

Added preview Data for tables and columns

A new right-click menu has been added to tables and columns which will display a preview of the first 500 rows of data.

Extended Parameter Support to data types other than text

Previously parameters were always passed through as text based parameters. As of v2.16 you can now specify the data type for your parameters. This support is available both in the parameter dialog and in the XMLA parameter blocks.

When you specify @parameters in your DAX queries they will still default to the string data type, but there is a new dropdown which allows you to change this to one of the other supported datatypes (this list matches the parameter data types supported by Report Builder and Power BI Report Builder)

And if you choose the Write Parameter XML button or if you capture the query parameters using the All Queries trace those data types will also be reflected in the XML parameter block.

Added new version notification in title bar

When a new update is available there will be an update flag in the top right of the application and clicking on that flag will take you straight to the download page for that version.

Updated xmSQL cleanup to also fix table names

In the previous release of the xmSQL update feature we were cleaning up column names to match the display names, in this release this functionality was extended to also clean up table names.

Supporting all of the /f /s /d command line parameters at the same time

DAX Studio has always had support for the following command line parameters

/f <filename> – to open a .dax file
/s <server> /d <database> – to connect to a server and database

But prior to this release you could only use /f on it’s own. As of this release you can use all 3 of these parameters together.

Query Builder Enhancements

The Query Builder has a number of new features in this release which are outlined below.

Query Builder Updates
  1. There is a new Clear button at the top of the Query Builder which gives you a convenient single click to clear everything from the Query Builder.
  2. Now when you drag a column which has a Sort-by column the sort by column is added to the output list (this is required to support the next item)
  3. There is a new Order By pane, this is collapsed and all columns are sorted in ascending order by default.
  4. But you can expand this section and click on the columns there to switch them between sorting Ascending, Descending or ignored.
  5. There is a new Auto-Generate button. When you click on this button the query generated by the query builder will appear in the edit window and will be updated in real time as you make changes to the Query Builder
  6. Clicking the Edit Query button will now update any previously generated query rather than adding a new version underneath.

Extending installer support for Windows ARM64

The installer used to do a platform check for x86 or x64, this has been extended to allow installing on ARM64 since that platform now has an x64 emulation layer.

Other Enhancements

  • #620 Adding Ctrl+W to select current word
  • #584 Extending Hover tooltip to work with Keywords
  • Custom Key-Bindings moved out of preview
  • #636 Show PBIX filename instead of database ID in the database dropdown when connected to Power BI Desktop
  • #638 Adding encoding option when exporting to CSV
  • updating ADOMD / AMO references to 19.22

Preview Features

Debug Commas

This command moves commas in formatted queries to the start of the line. This re-formats the selected text so that you can more easily comment out sections of code while debugging.

Note: this preview feature replaces the swap delimiters button in the ribbon.

Show XMLA Commands in All Queries trace

This option is useful for viewing commands sent by other tools like SSDT and Tabular Editor.

Fixes

  • #578 Analyze in Excel not working with PBI XMLA or AzureAS
  • #579 Server Timings Layout Tab not appearing
  • Improved error message when no query text is specified
  • #581 All Queries Trace against PowerPivot caused crash
  • Fixed a crash when attempting to add a display folder to the Query Builder
  • Fixed a crash when attempting to use the query builder against a model with an invalid calculation script
  • #592 datatypes not syntax highlighted and not in code completion
  • #613 DMV and Function drag/drop not working
  • #647 Hiding hidden objects was not working correctly with items in display folders
  • #643 fixing issue with code completion window “sticking”
« Older posts