DAX Context and Row Alteration

Yes, you can alter the row context within a measure using DAX functions. DAX (Data Analysis Expressions) is a formula language that allows you to perform custom calculations on data in Microsoft Power Pivot, Analysis Services, and Power BI.

DAX Row and Filter Context

In DAX, an important concept to understand is the row context. Row context refers to the context in which DAX formulas are evaluated - for a particular row or for the entire table.

However, it's also important to understand filter context, which filters your results based on certain criteria from your data model or visuals.

Changing the Row Context within a Measure

To change or propagate row context within a measure, you can use certain iterative DAX functions like SUMX, AVERAGEX, MAXX, etc. These functions can modify the row context because they iterate over rows in a table (or related tables).

Here is an example using SUMX which sums the result of an expression evaluated for each row in a table.

Total Sales = SUMX(
    'Sales',
    'Sales'[Quantity]*'Sales'[Unit Price]
)

In the above SUMX example, for each row in the 'Sales' table, the measure multiplies the 'Quantity' by 'Unit Price', and then adds up those results to give the total sales.

Please note, if your purpose is to filter the row context, consider using conditional functions such as CALCULATE and FILTER, as they modify the filter context, not a row context.

However, redefining or removing the row context entirely requires advanced methods and is beyond the scope of DAX basics.

Learning More

To mastery in DAX especially about contexts, I would recommend you go through the relevant courses available on the Enterprise DNA platform. The tutorials are comprehensive, well-structured, and suitable for both beginners and experienced professionals.