Created by: Paul Pitcher
Creation Date: Aug 16, 2025
Updated Date: Oct 14, 2025

Power Query

(also called "Power Query editor", "Query editor")
- Wiki page
-is an ETL tool created by Microsoft
-as you interact with the GUI interface of Power Query behind the scene a M code file is being modified (tip: see the section called "M" above for additional information). You don't have to know M code to pass the PL-300 exam, but it is worth looking at anyway. There are some things that you can do directly in M code that you can't do in the Power Query GUI interface.

Q: Where do I find/open Power Query?
A: From what i can tell this isn't as straight forward as it should be. There are 2 ways to get to "Power Query"
1. if you have a power BI workbook open and you want to change the data that you are working with you would click on "Transform data" (I think that this button should be called "Power Query"). When you do this a new window will open that allows you to modify the data that you are bringing into your Power BI workbook. This new window is "Power Query". The interesting thing is that this new window that opens doesn't actually say "Power Query" on the bar at the very top. I've seen some YouTube videos where it does, but on my install of Power BI it does not say this.

Tip: if you click on the "Transform data" and then hover over the "Transform data" in the pull-down list you will see

So as far as I know this is the only way that I know that I'm using "Power Query".

2. If you are loading data for the first time you are given a chance to "Load" the data as it is, or you can transform the data by clicking on the "Transform Data" button, which will open a new window which is "Power Query" once again I wish that you were being told that you are going to transform the data using "Power Query"

Tip: Power query is used in several different tools at Microsoft. Power BI is just one of them.

Q: is "Power Query" also called the "query editor" or is the "query editor" a separate tool?
A: from what I have seen some people use "Power Query", "Power Query editor", and "query editor" interchangeably.

Tip: you can open the same table 2 times. For example I could use power Query to open up a table and show columns 1,2,3. And then I could open up the table again and this time only show columns 3,4,5.

Q: I have a power BI report that pulls from a text file. a new column has been added to the text file. I would think that if i open power query and press the "Refresh Preview" button that i would see the new column but i don't. How do i see the new column that has been added?
A: answer from this website: azure - Refresh powerBI data with additional column - Stack Overflow
A: Pauls Answer: i completely agree with what you have said. i would make the same assumption as well. To solve this issue you will need to go to the "Home" tab, and then you will need to go to the "Query" section and click on the "Advanced Editor" button.
In this example I have a text file that initially had 2 columns of data. I have now added a 3rd column of data, however it isn't showing up in Power Query.

We are going to edit this line of M code
Columns=2,
if we change it to
Columns=3,
then we will see the 3rd column

if we change it to
Columns=4,
then we will see an empty 4th column

if we change it to
Columns=null,
then when ever a column is added or removed and we refresh the data we will see the current number of columns in the text file.

Tip: you can even refresh from the "Report view" and you will see new columns that are added. That really nice.

Q: In my database the first column is a key column that I like to see first when ever I look at this data set. The problem that I am facing is that the columns are in alphabetical order, not the order that they are in the databases. How can I change this?

A: Sep 1, 2025 None that I know of.