COUNT FUNCTION DAX

The COUNT function is a power bi DAX statistical function which counts the number of rows in a table.

It returns a single integer value.

It ignores blank values in counting, allows only values of data types : String, Number and dates.

It does not support Boolean values (TRUE/FALSE).

The only argument allowed to this function is a column.

DAX SYNTAX

COUNT(<column>)

<column> is the column that contains the values to be counted.

Lets go through an example to see COUNT() Function in action.

Here we have a sample table which consist a registration data of students

Lets create a measure which use the count() function and returns total rows counts.

Count_Rows = Count(Registration[ID])

You can see, the measure output by dragging it into card visual that is 10.

Count() Function does not support boolean(TRUE/FALSE) values 

To demonstrate this, Lets use Count() Function to count the Boolean values.

Here we have boolean column named as Flag, Lets see count () function with boolean column.

Count_boolean = COUNT(Registration[Flag])

Once you drag this measure to card visual, It gives an error as shown in below screenshot.