Problem Statement: Disco Yes/No Calculation

The provided DAX snippet aims to generate a calculated column or measure titled "Disco Yes/No" that counts the number of disconnect entries for each user. However, there are several issues present in the DAX code that need to be addressed for it to function properly.

Issues Identified

1. Syntax Errors: There are missing parentheses and incorrect syntax that lead to potential evaluation errors.
2. Logical Errors: The filtering logic for DisconnectDate is poorly defined, leading to incorrect data counting.
3. Usage of RELATEDTABLE(): This function may not be necessary in this context if the output does not depend on filtering related tables.

Proposed Solution

The revised DAX code employs the following strategies:

• Correctly structure your SUMMARIZE function.
• Use appropriate filtering and logical conditions.
• Properly format ROW and other DAX functions for clarity.

Corrected DAX Code

Disco Yes/No = 
VAR DiscoRows =
    ADDCOLUMNS(
        SUMMARIZE(
            'NEW.DIM_Bills',
            'NEW.DIM_Bills'[UserName],
            'NEW.DIM_Bills'[DisconnectDate],
            'NEW.DIM_Bills'[BillId]
        ),
        "CircuitID", CALCULATE(COUNTROWS(RELATEDTABLE('NEW.DIM_Circuits')))
    )
RETURN
    COUNTROWS(
        FILTER(
            DiscoRows,
            NOT(ISBLANK('NEW.DIM_Bills'[DisconnectDate])) // Ensure DisconnectDate is not blank
        )
    )

Explanation of the Code

1. ADDCOLUMNS: This function is used to add a new calculated column (CircuitID) within the previously summarized table.

2. SUMMARIZE: This generates a summary table grouped by UserName, DisconnectDate, and BillId.

3. CALCULATE: A count of related circuits is calculated to populate the CircuitID column. This avoids using unrelated tables which could lead to confusion.

4. FILTER: The FILTER function evaluates rows from DiscoRows, ensuring that only those with a non-blank DisconnectDate are counted.

5. COUNTROWS: Finally, we count the rows output from the FILTER function, yielding the total count of disconnect events.

Usage Example

Assuming you are setting this measure ("Disco Yes/No") in Power BI, you would then place it in a report visualization to represent the number of disconnects per user. It can be displayed next to the user's information for analytical insights.

This DAX expression efficiently counts all disconnect entries for users in the dataset while adhering to the principles of clarity, maintainability, and performance.

By following these practices, users can ensure that their DAX measures are robust, readable, and functional. Additional resources on advanced DAX techniques can be found on the Enterprise DNA platform for further learning.