Applied steps and undo in Power BI - Dashboard Guide

Dashboard Mode - Applied steps and undo

Dashboard Goal

Understand how Power BI's Applied Steps and Undo features help track and reverse data transformation changes during data preparation.

Sample Data

OrderID	Product	Quantity	Price	OrderDate
1001	Notebook	2	5	2024-01-10
1002	Pen	5	1	2024-01-11
1003	Notebook	3	5	2024-01-12
1004	Marker	4	2	2024-01-13
1005	Pen	6	1	2024-01-14

Dashboard Components

• Applied Steps Pane: Shows the list of transformation steps applied to the data in Power Query. Example steps:
  • Source: Load original data
  • Changed Type: Set correct data types
  • Filtered Rows: Remove orders with Quantity < 3
  • Added Custom Column: TotalCost = Quantity * Price
• Undo Button: Allows reversing the last applied step. For example, undoing the filter step will bring back orders with Quantity < 3.
• Data Preview Table: Shows the current state of data after applied steps. For example, after filtering Quantity >= 3, only orders 1003, 1004, and 1005 appear with an added TotalCost column.
• Formula Bar: Displays the M code for the selected applied step, e.g., = Table.SelectRows(Source, each [Quantity] >= 3).

Dashboard Layout

+----------------------+--------------------+
| Applied Steps Pane    | Data Preview Table |
| (List of steps)      | (Filtered data)    |
+----------------------+--------------------+
| Formula Bar (M code)                      |
+------------------------------------------+
| Undo Button                              |
+------------------------------------------+

Interactivity

Clicking on an applied step updates the Data Preview Table to show data at that step. The Formula Bar updates to show the M code for that step. Clicking Undo removes the last step and updates both the Applied Steps Pane and Data Preview Table accordingly.

Self Check

If you undo the last step (filter Quantity >= 3), which orders appear in the Data Preview Table?

• Orders 1001, 1002, 1003, 1004, and 1005 appear because the filter is removed.
• The Applied Steps Pane no longer shows the filter step.

Key Result

Shows how applied steps and undo feature in Power BI Power Query track and reverse data transformations.

Practice

1. What is the main purpose of Applied Steps in Power BI's Query Editor?

easy

A. To write DAX formulas for calculations

B. To create visualizations automatically

C. To track and record every change made to the data during cleaning

D. To connect Power BI to external databases

Solution

1. Step 1: Understand Applied Steps function

   Applied Steps record each transformation or change you make to your data in Query Editor.

2. Step 2: Differentiate from other features

   Applied Steps do not create visuals, write formulas, or connect databases; they track data cleaning actions.

3. Final Answer:

   To track and record every change made to the data during cleaning -> Option C

4. Quick Check:

   Applied Steps = Track changes [OK]

Hint: Applied Steps = your data cleaning history [OK]

Common Mistakes:

• Confusing Applied Steps with visualization features
• Thinking Applied Steps write formulas
• Assuming Applied Steps connect to databases

2. Which of the following is the correct way to undo the last applied step in Power BI Query Editor?

easy

A. Click the 'X' next to the last step in the Applied Steps pane

B. Press Ctrl + Z anywhere in Power BI Desktop

C. Delete the entire query and start over

D. Right-click the data table and select 'Undo'

Solution

1. Step 1: Locate Applied Steps pane

   The Applied Steps pane shows each change; each step has an 'X' to remove it.

2. Step 2: Undo last step by removing it

   Clicking the 'X' next to the last step removes that change, effectively undoing it.

3. Final Answer:

   Click the 'X' next to the last step in the Applied Steps pane -> Option A

4. Quick Check:

   Undo last step = Click 'X' [OK]

Hint: Undo last step by clicking 'X' in Applied Steps [OK]

Common Mistakes:

• Using Ctrl + Z which doesn't undo Query Editor steps
• Deleting entire query unnecessarily
• Looking for undo option outside Applied Steps

3. Given these Applied Steps in Power BI Query Editor:
1. Source
2. Removed Columns
3. Filtered Rows

If you click the 'X' next to Removed Columns, what will happen?

medium

A. Both 'Removed Columns' and 'Filtered Rows' steps will be deleted

B. 'Removed Columns' step will be deleted, and 'Filtered Rows' will be recalculated without it

C. Only 'Filtered Rows' step will be deleted

D. Nothing will change because you cannot delete middle steps

Solution

1. Step 1: Understand step dependencies

   Deleting a middle step removes that transformation; later steps recalculate based on remaining steps.

2. Step 2: Effect on later steps

   'Filtered Rows' depends on the data after 'Removed Columns'; it will recalculate using data without that removal.

3. Final Answer:

   'Removed Columns' step will be deleted, and 'Filtered Rows' will be recalculated without it -> Option B

4. Quick Check:

   Deleting middle step recalculates later steps [OK]

Hint: Deleting a step recalculates all following steps [OK]

Common Mistakes:

• Assuming all later steps delete automatically
• Thinking middle steps cannot be deleted
• Believing nothing changes after deletion

4. You accidentally removed a column in Power BI Query Editor but did not want to. Which of these is the best way to fix it?

medium

A. Create a new query from scratch

B. Close Power BI without saving and reopen the file

C. Manually add the column back using DAX

D. Undo the removal by deleting the 'Removed Columns' step in Applied Steps

Solution

1. Step 1: Identify the mistake step

   The 'Removed Columns' step is where the column was removed.

2. Step 2: Undo by deleting the step

   Deleting this step in Applied Steps will restore the column as if it was never removed.

3. Final Answer:

   Undo the removal by deleting the 'Removed Columns' step in Applied Steps -> Option D

4. Quick Check:

   Undo mistake by deleting step [OK]

Hint: Fix mistakes by deleting wrong Applied Steps [OK]

Common Mistakes:

• Closing without saving loses all work
• Trying to add columns with DAX instead of Query Editor
• Rebuilding query unnecessarily

5. You applied these steps in order:
1. Changed Type
2. Filtered Rows
3. Added Custom Column

Later you realize the 'Changed Type' step was incorrect. What is the best approach to fix this without losing your custom column?

hard

A. Delete the 'Changed Type' step and then reapply it correctly before the other steps

B. Delete all steps and start over from the source

C. Edit the 'Added Custom Column' step to fix the type issue

D. Ignore the error and proceed with the current steps

Solution

1. Step 1: Remove incorrect 'Changed Type' step

   Delete the wrong 'Changed Type' step to remove the incorrect data type changes.

2. Step 2: Reapply correct 'Changed Type' step before other steps

   Reapply the correct type changes before 'Filtered Rows' and 'Added Custom Column' to keep data consistent.

3. Final Answer:

   Delete the 'Changed Type' step and then reapply it correctly before the other steps -> Option A

4. Quick Check:

   Fix errors by correcting early steps without losing later ones [OK]

Hint: Fix early step errors by deleting and reapplying them [OK]

Common Mistakes:

• Deleting all steps loses work
• Editing later steps to fix early errors
• Ignoring errors causes wrong data