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The Definitive Guide to Power Query (M)

You're reading from   The Definitive Guide to Power Query (M) Mastering complex data transformation with Power Query

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Product type Paperback
Published in Mar 2024
Publisher Packt
ISBN-13 9781835089729
Length 758 pages
Edition 1st Edition
Languages
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Authors (3):
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Greg Deckler Greg Deckler
Author Profile Icon Greg Deckler
Greg Deckler
Melissa de Korte Melissa de Korte
Author Profile Icon Melissa de Korte
Melissa de Korte
Rick de Groot Rick de Groot
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Rick de Groot
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Toc

Table of Contents (19) Chapters Close

Preface 1. Introducing M FREE CHAPTER 2. Working with Power Query/M 3. Accessing and Combining Data 4. Understanding Values and Expressions 5. Understanding Data Types 6. Structured Values 7. Conceptualizing M 8. Working with Nested Structures 9. Parameters and Custom Functions 10. Dealing with Dates, Times, and Durations 11. Comparers, Replacers, Combiners, and Splitters 12. Handling Errors and Debugging 13. Iteration and Recursion 14. Troublesome Data Patterns 15. Optimizing Performance 16. Enabling Extensions 17. Other Books You May Enjoy
18. Index

Parameters and Custom Functions

The M language is a functional language containing hundreds of functions suited for a great number of tasks. At first, the standard function library will likely meet most of your transformation needs. However, once you run into more challenging situations with the M language, you will find that being able to write your own custom functions opens up new possibilities; it can greatly simplify the data transformation process and make it so you can easily repeat complex logic. This is especially true when you leverage a feature like creating a function, which allows you to transform existing queries into dynamic, reusable functions. The biggest benefit here is that you can set up your logic once and apply it with ease everywhere else. If you need to modify your logic later, simply update your function. This change will automatically propagate to all queries using that function.

Accordingly, this chapter covers the following:

  • Parameters
  • ...
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