Creating calculated columns and measures using DAX

 DAX (Data Analysis Expressions) is a powerful formula language used in Power BI for creating calculated columns and measures. Here's how you can create them:

Calculated Columns:

Calculated columns are computed row by row in a table. They can be used for tasks like concatenating strings, performing mathematical operations, or applying logical conditions on existing columns.

To create a calculated column:

1. Navigate to Data View:
• In Power BI Desktop, click on the "Data" view.
2. Select Table:
• Select the table for which you want to create the calculated column.
3. Click on "New Column":
• In the "Modeling" tab, click on "New Column".
4. Write DAX Expression:
• Write your DAX expression in the formula bar.
• For example, let's say you want to create a calculated column "TotalMarks" in the "Students" table which sums up the marks of different subjects:

                       TotalMarks = [Math] + [Science] + [English]

 

Measures:

Measures are calculations performed at the aggregate level, typically over an entire table or a filtered set of data. They are dynamic and respond to changes in filters and slicers.

To create a measure:

1. Navigate to Report View:
• Click on the "Report" view.
2. Click on "New Measure":
• In the "Modeling" tab, click on "New Measure".
3. Write DAX Expression:
• Write your DAX expression in the formula bar.
• For example, let's say you want to create a measure "AverageGrade" which calculates the average grade of students:

                          AverageGrade = AVERAGE(Students[Grade])

4.            4. Use Measure in Visualizations:

• Drag and drop the newly created measure into your visualizations.

 

Example:

Let's say we have a table named "Sales" with columns "Quantity" and "PricePerUnit". We want to create a calculated column for "TotalPrice" and a measure for "TotalSales".

Calculated Column:

           TotalPrice = Sales[Quantity] * Sales[PricePerUnit]

               Measure:

          TotalSales = SUM(Sales[TotalPrice])

Once created, you can use these calculated columns and measures in your visualizations and reports to analyze your data effectively.