Why dataflows centralize data preparation in Power BI - Formula Trace Breakdown

Sample Data

Sample customer data from different sources before centralizing with dataflows.

Cell	Value
A1	CustomerID
B1	Name
C1	Country
A2	101
B2	Alice
C2	USA
A3	102
B3	Bob
C3	Canada
A4	103
B4	Charlie
C4	USA

Formula Trace

Table.TransformColumns(Source, {"Country", Text.Upper})

Step 1: Source

Step 2: Table.TransformColumns(Source, {"Country", Text.Upper})

Cell Reference Map

    A       B        C
1 CustomerID Name    Country
2 101        Alice   USA
3 102        Bob     Canada
4 103        Charlie USA

Arrow: 'Country' column is transformed to uppercase

The formula references the 'Country' column (C2:C4) to apply uppercase transformation.

Result

    A       B        C
1 CustomerID Name    Country
2 101        Alice   USA
3 102        Bob     CANADA
4 103        Charlie USA

After transformation, the 'Country' column has standardized uppercase values, centralizing data preparation.

Sheet Trace Quiz - 3 Questions

What does the formula Table.TransformColumns(Source, {"Country", Text.Upper}) do?

A Converts all values in the 'Country' column to uppercase

B Filters rows where 'Country' is uppercase

C Deletes the 'Country' column

D Adds a new column with uppercase country names

Key Result

Table.TransformColumns applies a function to transform values in a specified column.