Explore the Power Query M Language with tutorials, cheat sheets, examples, and PDF guides. Unlock advanced data transformation in Power BI using M code.
What is Power Query M Language?
The Power Query M Language—often just called M—is the scripting language that powers data transformations in tools like Power BI and Excel. Every step you take in Power Query’s graphical editor is converted into M code under the hood.
It’s a functional, case-sensitive language built to handle complex data extraction, cleaning, and reshaping before your data ever reaches a visualization.
Why Use M Language?
While the Power Query interface is user-friendly, it has limits. To perform dynamic filtering, parameter-driven logic, or reusable functions, you need to work with Power Query M formulas directly.
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Learning M can help you:
- Create custom steps that the UI doesn’t offer
- Optimize performance in large data models
- Automate repeated transformations
- Write reusable and shareable logic
Power Query M Cheat Sheet (Quick Syntax Guide)
If you’re just getting started, use this quick Power Query M cheat sheet to understand its basic structure:
let
Source = Excel.CurrentWorkbook(){[Name=”Data”]}[Content],
Filtered = Table.SelectRows(Source, each [Amount] > 1000)
in
let…in is the core structure
You can declare multiple steps inside let
Each transformation is applied step-by-step
This structure is easy to read and very flexible. For more shortcuts, search for Power Query M cheat sheet PDF online for free downloadable references.
Real Power Query M Examples You Can Use
1.Filter Non-Blank Rows
Table.SelectRows(Source, each not List.IsEmpty(List.RemoveMatchingItems(Record.FieldValues(_), {“”, null})))
2.Date Filter for Last 30 Days
let
Today = DateTime.Date(DateTime.LocalNow()),
RecentData = Table.SelectRows(Source, each [Date] >= Date.AddDays(Today, -30))
in
RecentData
3.Create a Custom Tax Function
let
CalculateTax = (amount as number) => amount * 0.18
in
CalculateTax
These Power Query M examples show how to move beyond the GUI into more advanced automation.
Beginner-Friendly M Language Tutorial
Want to go from beginner to pro? Try a Power Query M Language tutorial available for free across YouTube or Microsoft Learn. Topics usually covered:
- Writing M code manually
- Debugging queries
- Building reusable custom functions
- Performance tuning with query folding
If you’re looking specifically for Power BI integration, search for Power BI M Language tutorial to find use-case driven lessons.
Get the Power Query M Language PDF
Many data pros recommend having a Power Query M Language PDF or cheat sheet on hand. These PDF guides list common:
- Table and list functions
- Logical operators
- Syntax structures
- Custom function patterns
Just search for “Power Query M Language cheat sheet PDF” and you’ll find excellent community-curated and official Microsoft versions.
Official M Language Documentation
Microsoft offers detailed Power Query M Language documentation on its Learn platform. It includes:
- Complete function reference
- Connector support
- Error-handling techniques
- Syntax rules
Bookmark the page and keep it as your go-to reference when working in the Advanced Editor.
Power Query Formula Language M vs DAX
Don’t confuse Power Query M with DAX. M is used for data loading and transformations, while DAX is used for modeling and calculations after data is loaded into Power BI.
M = Clean the data
DAX = Analyze the data
Both are essential, but they serve very different purposes in your BI workflow.
Final Words
The Power Query M Formula Language gives you precision control over data transformations in Power BI and Excel. By mastering M, you’ll be able to solve complex data problems, build reusable query logic, and make your reports faster and smarter.
Start small with cheat sheets and examples, then gradually move on to writing custom functions and working with APIs. Don’t forget to refer to the official M documentation and tutorials to deepen your understanding and improve your knowledge for better future & career growth.