Resources
PQM.guide wouldn't exist without the work of many people across the Power Query community. This page highlights tools, references, and learning materials that we think every M developer should know about.
Tools
PQLint.com
An automated linter for Power Query M code. Paste in your query and get instant feedback on best practices — from consolidating type changes to avoiding query-folding pitfalls. Many of the best-practice tips throughout PQM.guide were informed by PQLint's rule set.
TMDL VS Code Extension
Microsoft's official VS Code extension for working with Tabular Model Definition Language (TMDL) files. Includes M code syntax highlighting, autocomplete, diagnostics, hover info, and formatting for Power Query expressions embedded in TMDL documents — making VS Code a first-class editor for M code.
Learning
Power Query M Primer — Ben Gribaudo
A comprehensive multi-part blog series that walks through the M language from the ground up. Covers everything from simple expressions and let blocks to advanced topics like type system internals, metadata, and custom connectors. If you want to truly understand M rather than just copy-paste snippets, this is the place to start.
Official Power Query M Reference — Microsoft Learn
The official language specification and function reference from Microsoft. PQM.guide builds on top of this documentation by adding visual examples and community-sourced best practices, but the official docs remain the authoritative source for language semantics.
The BIccountant — Imke Feldmann
A long-running blog packed with advanced Power Query techniques, creative M solutions, and deep dives into real-world data transformation challenges. Imke's posts frequently explore lesser-known M patterns and push the boundaries of what's possible in Power Query.
Books
M Is for (Data) Monkey — Ken Puls & Miguel Escobar
A beginner-friendly guide to Power Query that introduces M through practical, hands-on examples. Covers the fundamentals of transforming and shaping data in Excel and Power BI, making it an excellent starting point for anyone new to the language.
The Definitive Guide to Power Query (M) — Greg Deckler, Rick de Groot & Melissa de Korte
A thorough reference covering M from foundational concepts through advanced patterns. Ideal for users who want to go beyond the UI and write M code directly, with in-depth coverage of functions, types, error handling, and query optimization.
Community
ImkeF/M — Custom M Function Library
A collection of custom M functions for Power Query and Power BI maintained by Imke Feldmann. These reusable functions can be packaged as a library and cover common data transformation patterns that go beyond the built-in standard library.
ImkeF/M-Guide — Native M Function Gotchas
A collection of native M functions with unexpected behaviour and their workarounds. An invaluable reference for understanding edge cases and quirks in the standard M library that can trip up even experienced developers.
DAX.guide
The inspiration for this project. DAX.guide is the gold standard for DAX function documentation — clear syntax references, practical examples, and community contributions. PQM.guide aims to bring the same approach to the Power Query M language.
Know of a resource that should be listed here? Open a PR or start a discussion on GitHub.