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Append Queries in Power Query: Combine Files Easily
Appending stacks tables with the same shape: a January table and a February table become one. Column matching and failure modes.
Category
Power Query
ETL and data preparation in Power BI.
13 tutorials in this category
Power Query is the part of Power BI that runs before any DAX does: connecting to a source, fixing the column types, unpivoting the month columns, merging in the lookup table. Every click in the editor writes M code, and that code is what actually executes — on refresh, against the source, possibly on a schedule you are not watching.
The sensible reading order is the getting-started walkthrough, then the transformations you will use every week (group by, unpivot, merge, append, conditional columns), then the M language underneath. Query folding belongs early too, even for beginners: folding is the difference between a refresh that takes four seconds and one that takes forty minutes, and a single step in the wrong place can break it without any error message appearing.
What this section deliberately avoids is doing work in Power Query that belongs in the model, or vice versa. Cleaning that never changes should happen upstream and be forgotten; logic that changes with every report belongs in a measure. Most slow models we look at are a case of that boundary being crossed in both directions at once.
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Merge Queries in Power Query (VLOOKUP Equivalent)
Merge queries in Power Query as a VLOOKUP replacement. Prepare both tables, pick the join kind, expand columns, and handle unmatched rows in a worked example.
TRANSFORM / CLEAN
Import and Transform Excel Data with Power Query
Excel is where most Power BI projects start. How to import workbooks, fix merged headers and bad types, and build a refresh that survives a file move.
TRANSFORM / CLEAN
How to Integrate Power BI with Excel: 4 Working Setups
Four ways Excel and Power BI work together: shared Power Query logic, Analyze in Excel, CSV export, and PivotTables on a dataset. Plus the write-back limits.
TRANSFORM / CLEAN
Query Folding in Power BI: What Breaks It & How to Check
Folding turns applied steps into one query the source runs itself. See what breaks it, how to check with View Native Query, and which sources support it.
TRANSFORM / CLEAN
Unpivot in Power Query: Wide to Long, Correctly
Month-by-column reports become a tidy long table in three clicks. The exact steps, the column to keep fixed, and the usual pitfall.
TRANSFORM / CLEAN
Power Query Group By: Count, Sum & All Rows Without Formulas
Group rows by one or more columns without writing a formula: count, sum, average, min, max and All Rows. See the generated M and why totals look wrong.
TRANSFORM / CLEAN
Power Query: Add a Column With an If Statement
Add a new column with an if statement in Power Query, without writing M. The dialog, nested conditions, generated code, and bucketing patterns.
TRANSFORM / CLEAN
10 Power Query Transformations Every Analyst Needs
Ten Power Query steps that handle the messy exports analysts actually get: inconsistent names, merged headers, malformed dates.
TRANSFORM / CLEAN
Power Query Parameters: Build Dynamic, Reusable Data Sources
Swap environments, date ranges or test data from a dropdown instead of editing M code. How to create parameters and pass them in.
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Merge vs Append in Power Query: Which One?
Merge is a join that adds columns. Append is a union that stacks rows. The difference, the join types, and which one costs more to refresh.
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Power Query M Language: Tables, Records & Functions
M is a functional language, not a spreadsheet formula. See how tables, records and lists fit together, how let expressions compose, and how to read M code.
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Getting Started with Power Query in Power BI
New to Power Query? This beginner guide covers the editor, applied steps, common transformations, and why query folding matters for refresh performance.