Counts the number of distinct values in a column.
The column for which the distinct values are counted.
The number of distinct values in ColumnName.
The only argument allowed to this function is a column. You can use columns containing any type of data. When the function finds no rows to count, it returns a BLANK, otherwise it returns the count of distinct values.
Learn more about DISTINCTCOUNT in the following articles:
Related Distinct Count
The Related Distinct Count pattern allows you to apply the distinct count calculation to any column in any table in the data model. Instead of just counting the number of distinct count values in the entire table using only the DISTINCTCOUNT function, the pattern filters only those values related to events filtered in another table. » Read more
Analyzing the performance of DISTINCTCOUNT in DAX
This article describes how to analyze the performance of a DAX measure based on a DISTINCTCOUNT calculation and how to evaluate possible optimizations. » Read more
Other related functions are:
Contributors: Alberto Ferrari, Marco Russo
MSDN documentation: https://docs.microsoft.com/en-us/dax/distinctcount-function-dax