DAX Function to Count "Yes" Values

Overview

This section outlines the DAX function that counts the occurrences of the value "Yes" in a specified column of a table. This function can be useful for analyzing survey responses or binary yes/no data.

Function Definition

CountYesValues = 
    VAR YesCount = 
        CALCULATE(
            COUNTROWS(TableName), 
            TableName[ColumnName] = "Yes"
        )
    RETURN
        YesCount

Documentation Block

CountYesValues

Purpose:
Counts the number of occurrences of the value 'Yes' in a specified column of a specified table.

Parameters:
- TableName: The name of the table where the data is stored.
- ColumnName: The name of the column being evaluated.

Returns:
- Integer: The count of 'Yes' values in the specified column.

Exceptions:
- Raises an error if the specified table or column does not exist.

Input Validation

In the context of DAX, there is limited input validation. However, if TableName or ColumnName do not exist, the code will error out when executed, which should be handled at the reporting level or by ensuring proper schema consistency.

Logic Explanation

• VAR YesCount: This variable calculates the number of rows where the ColumnName equals "Yes" using the CALCULATE and COUNTROWS functions.
• CALCULATE: Modifies the filter context to only those rows where the column matches "Yes".
• RETURN: Finally, this returns the count stored in the YesCount variable.

Example Usage

Suppose we have a table called SurveyResponses with a column named Response. To count how many respondents answered "Yes", you would define the measure as follows:

CountYesResponses = 
    VAR YesCount = 
        CALCULATE(
            COUNTROWS(SurveyResponses), 
            SurveyResponses[Response] = "Yes"
        )
    RETURN
        YesCount

You can then use CountYesResponses in your reports or dashboards to display the total number of 'Yes' responses.

Final Notes

This DAX measure is efficient for counting values and can be scaled for larger datasets. To build on your DAX skills, consider exploring various resources on the Enterprise DNA Platform for in-depth learning on advanced DAX techniques and best practices.