In this video, I explain one of the most underrated techniques in Power Query: using empty lists ({}) to make your data-cleaning steps more flexible, error-proof, and dynamic.
You’ll learn:
🔹 How empty lists work in Power Query
🔹 Why using {} is safer than hard-coding column names
🔹 How empty lists prevent errors when columns are missing
🔹 Practical examples using:
Table.UnpivotColumns → unpivot all columns except specific ones
Table.TransformColumns → transform only columns that actually exist
🔹 How empty lists make your queries more robust when the source file changes
🔹 Real-world scenarios where empty lists are essential for Excel & Power BI cleaning
00:00 Introduction
00:42 Table.TransformColumns
02:05 Table.UnpivotOtherColumns
