Power Query: data preparation and training

Who is this article for?

For professionals and learners who want to understand this skill, its practical uses and the progression required before choosing or continuing training.

What you need to understand

Power Query is Microsoft’s data connectivity and preparation technology used in Excel, Power BI and other products. It imports sources, cleans and reshapes data, and repeats the same transformations on refresh.

The skill must be connected to a business need, identified data or information, an expected outcome and control criteria. Professional mastery is measured by reliable, explainable results rather than the number of features known.

Why this skill matters today

This skill supports growing needs around productivity, data quality, analysis, automation and changing job practices. Its value still depends on the use case and on integration into a real process.

For organisations, the priority is therefore to build method, controls and real-world practice rather than simple tool familiarity.

What you actually do with this skill

Import sourcesAutomatically combine files from a folder, Excel sheets, CSVs or database sources into one repeatable query.

Clean dataStandardise types, labels, dates, columns and missing values through visible, reproducible transformation steps.

Merge tablesReconcile reference and transaction tables through merges or appends while checking keys and unmatched rows.

Create repeatable rulesReplace a sequence of manual cleanup operations with M steps that run again every time data refreshes.

Diagnose queriesIdentify slow steps, source errors or unnecessary transformations to make queries more robust and maintainable.

Putting the skill into practice

A professional needs to solve a recurring task with an outcome that can be checked and handed over.

Problem : Reduce processing time without losing quality.

Context : Real data, business constraints and validation rules.

Skills : Get Data, Types, Applied steps, Merge, Append.

Example : Import sources inside a defined workflow.

Hands-on application : Test several cases, document limitations and keep the appropriate validation step.

Skills to master

BeginnerUnderstand foundations, vocabulary and the core workflow.

IntermediateApply the skill to realistic cases and combine related tools.

Advanced / autonomousDesign, control, document and improve the process autonomously.

Errors, limitations and points of attention

Starting with the tool before the problem.
Skipping verification of important outputs.
Ignoring data quality or access rights.
Building a process that cannot be reproduced.
Failing to document assumptions and limitations.

How to progress

BeginnerUnderstand foundations, vocabulary and the core workflow.

IntermediateApply the skill to realistic cases and combine related tools.

Advanced / autonomousDesign, control, document and improve the process autonomously.

Mandragore Learning Academy

Train with Mandragore Learning Academy

Mandragore Learning Academy connects this topic to training that actually exists in its catalogue. Courses are structured to progress from foundations to controlled professional practice.

The logic remains the same: understand, see a real case, know what to learn, then practise in the Learning Workspace.

View the related training →

Related training path

Mandragore Learning Academy connects this topic to training that actually exists in its catalogue. Courses are structured to progress from foundations to controlled professional practice.

Sources and references

Mandragore source: config_ia.php, config_dev.php and config_microsoft.php remain the source of truth for the training actually offered.

Microsoft Learn — Power Query documentation