Dynamically create types from text with Type.FromText in Power Query and Power BI

In this article I’ll show you how to create types from text in Power Query, enabling you to dynamically change types via functions for example. It’ll come out as a custom Type.FromText function which has been asked for in the comments of this article: https://www.thebiccountant.com/2017/01/09/dynamic-bulk-type-transformation-in-power-query-power-bi-and-m.

Problem

To transform a column to type text can be done like so:

Table.TransformColumnTypes(Source,{{"Column1", type text}})

This transforms the “Column1” from table “Source” to type text.  Now, if you want to make the type dynamic and move it to a function parameter like so:

(VariableType as type) =>

Table.TransformColumnTypes(Source,{{"Column1", VariableType}})

This returns a function dialogue as follows:

Read more

Performance tip for aggregations after joins in Power Query and Power BI

This article was edited on 2nd Nov 2019. JoinKind.Local has been removed to avoid problems with merges on tables with primary keys:

In this article you’ll learn how to speed up the aggregation of joined/merged tables by orders of magnitude (I recorded up to 30 times faster execution times). This method works for merges where both table have multiple rows for each keys. If one of your tables has a primary key, the method Chris Webb describes here works just as good: Chris Webb’s article on how to improve performance on aggregations after joins using primary keys .

You can follow along the different methods in this file:  PerformanceAggregationsAfterMerges1_Upload.zip

Background

When you join a table to another table in Power Query, the UI gives you the option to either expand the columns (default) or aggregate the contents of the joint tables. That’s useful if multiple rows are returned for the rows of the table that has been joined to (left table):

Read more

Power BI administration made easy with Power BI REST API custom connector

Today I read the (as always) great article by Matthew Roche “Governing Power BI just got a little easier” and couldn’t find a description on how to get to this promising window with all the admin goodness. So here it comes how to build your Power BI REST API custom connector then 😉 :

Create a custom connector for the Power BI REST API

Miguel Escobar has done a fantastic job to make it super-easy for you here.

Edit 30th September 2019: This repo has just been updated and includes a version with API secret. So if you’ve downloaded that content before and got an authorization error, please get the new files.

Get data from your connector

After you’ve stored the .mez-file in the correct folder (C:\Users\<YourUserNameGoesHere>\Documents\Power BI Desktop\Custom Connectors) and open Power BI Desktop again, you will be greeted with this warning message: Read more

DAX CALCULATE Debugger

CALCULATE is the most powerful function in DAX, as it allows you to change the filter context under which its expression is evaluated to your hearts content. But with big number of options to choose from, often comes big frustration when the results don’t match expectations. Often this is because your syntax to modify the filter context doesn’t do what you’ve intended. Unfortunately CALCULATE only displays its result and not how it achieved it, so debugging becomes a challenge. This is where my CALCULATE Debugger measure can help out:

DAX CALCULATE Debugger

This is a measure that returns a text-value, showing the number of rows of the adjusted filter context table, the MIN and MAX value of the selected column as well as up to the first 10 values. Just place this measure beneath the CALCULATE-measure in question and try to find the error 😉

Read more

The full Table.ContainsAnywhere function for Power Query in Power BI and Excel

In a previous post I introduced the concept of a function that searches for an occurrence of a character or string within all columns of a table. Here I share the full “Table.ContainsAnywhere” – function with parameters for many useful options.

Function parameters and options

  1.  The first parameter “MyTable” refers to the table to search through
  2.  The 2nd parameter “MySearchStrings” can be either a text field or a list of strings to be searched for. The function will take care of any of these cases automatically.
  3.  If the 2nd parameter is a list and this 3rd parameter is null or not speified, the function will return true if any of the list items is found within the table. But if set to “All”, all list items have to be found somewhere in the table for the function to return true.
  4.  By default, the search will be made in a case sensitive mode (as this is the default-mode in Power Query). But any entry into the 4th function parameter will turn this to a case insensitive mode instead.
  5.  By default, the string or list entry has to match fully with any entry in the table. Again, any entry in the 5th parameter swaps that to a partial match.

Read more

How to get more out of your Graph API custom connector in Power BI

The Graph API can deliver a huge amount of interesting data from your Microsoft 365-universe, but the Graph API custom connector for Power BI is not able to retrieve everything from it in its current shape. So I’ve modified it a bit to squeeze out a bit more of its sweet juice.

Problem

When trying to get the details for planner tasks, the following error-message appears:

Error in Graph API custom connector when retrieving details from planner tasks

Solution

Read more