DAX Formula for Sorting a Date Table

This document provides a DAX formula to sort a Date table. Sorting a Date table is typically done by creating a calculated column that extracts the key date information for sorting purposes.

Formula for Sorting

To sort a Date table, you can create a column that includes the year, month, and day, which facilitates a comprehensive sort. Below is a DAX formula that can be used:

SortDate = 
    FORMAT(DateTable[Date], "YYYYMMDD")

Explanation of the Formula

1. Column Creation:

   • The formula creates a new calculated column named SortDate in the existing DateTable.

2. FORMAT Function:

   • The FORMAT function is employed to convert the date into a text format that represents the date in a sortable format (YYYYMMDD).
   • This specific format ensures that sorting will be in chronological order.

Implementation Steps

1. Open Power BI Desktop.
2. Navigate to the Data view.
3. Select the Date table where you want to add the new sorting column.
4. Click on the "New Column" option.
5. Enter the provided DAX formula in the formula bar.
6. Rename the column to SortDate.

Sorting the Column in Power BI

After you have added the SortDate column, you need to set this column as the sort order for your Date column:

1. Select the original Date column in the Fields pane.
2. Go to the “Column tools” tab in the ribbon.
3. Click on the “Sort by Column” dropdown and select SortDate.

Example Scenario

Context

Assuming we have a DateTable with a single column named Date containing date values, this solution enables the correct chronological sorting of the Date column.

Data Before Sorting

Data After Implementing the Sort

After implementing the SortDate column and setting it as the sort order for Date, the table will display as follows when sorted:

Conclusion

The provided DAX formula facilitates the sorting of dates in a Date table within Power BI by creating a sortable text format of the date. Implementing these steps will ensure your Date table is sorted correctly for accurate data analysis and reporting.

For further learning, consider exploring the courses available on the Enterprise DNA platform to strengthen your DAX and data modeling skills.