In Power BI, DAX functions perform various calculations and manipulations on data. Two commonly used functions in Power BI DAX are USERNAME() and USERPRINCIPALNAME(). These functions are used to retrieve information about the current user and their identity, but they differ in their capabilities and the type of information they provide.
USERNAME()
USERNAME() returns the username of the current user as a text string. This function is typically used to identify the user who is currently using the Power BI report or dashboard. The USERNAME() function retrieves the name of the user that is logged in to the operating system, and it can be used in the calculation of measures, filters, and other expressions in DAX.
Syntax
User Name = USERNAME()Here,
User Name = Measure Name
USERNAME() = Function of the User name
For example, if you have a sales report that shows the sales by salesperson, you can use the USERNAME() function to filter the report to show only the sales of the currently logged-in salesperson. You can also use the USERNAME() function in a measure to calculate the total sales of the current user.
Limitations:
The USERNAME() function only retrieves the username of the current user who is logged into the system.
This function does not provide any additional information about the user such as their email address or department.
It is not suitable to perform more complex calculations or filtering based on user attributes.
USERPRINCIPALNAME()
The USERPRINCIPALNAME() function can be used to retrieve more detailed information about the current user, including the domain name and email address. This function is often used when integrating Power BI with other systems or when working with data sources that require more detailed user information.
Syntax
User Principal Name = USERPRINCIPALNAME()Here,
User Principal Name = Measure Name
USERPRINCIPALNAME = Function of the User Principal Name
For example, if you have a report that requires authorization based on user email addresses, you can use the USERPRINCIPALNAME() function to retrieve the email address of the current user and use it to filter the data in the report.
USERPRINCIPALNAME() will return the user principal name (UPN) of the current user as a text string. The user principal name is a unique identifier that is used to identify the user in the Active Directory domain. It is typically in the format of "username@domain.com".
Benefits:
The USERPRINCIPALNAME() function provides more information about the user than the USERNAME() function.
The user principal name can be used to identify the user's email address, department, or other attributes that are stored in Active Directory.
This function is useful to perform more complex calculations or filtering based on user attributes.
Conclusion
The main difference between USERNAME() and USERPRINCIPALNAME() in Power BI DAX is the type of information they provide. The USERNAME() function retrieves only the username of the current user, while the USERPRINCIPALNAME() function retrieves the user principal name, which typically includes the user's email address and other attributes that are stored in Active Directory. It is important to choose the appropriate function based on your requirements and the level of complexity needed for your calculations or filtering.