Excel: Count distinct values in a column using criteria from other columns

Question

I'm making a table to summarize a much larger table and I need to count the number of values from a column using criteria that can be found in another.

My data table looks for projects done look something like this:

|Project ID|Date|Person|Value|

The problem is, there are duplicate Project IDs because of multiple people that work on a specific project and countifs doesn't seem to work well here since it counts the duplicate values.

I'm trying to make a summary table where I have a distinct count of unique IDs based on the date.

|Date|Number of Unique IDs|

I found this answer here on stackexchange and was wondering if it can be done in excel?

SQL: Count distinct values from one column based on multiple criteria in other columns

Answer 1

You could use FREQUENCY to count the number of times a value occurs in a range so it can be done in Excel. This formula for example will count the number of different alphanumeric values present in the range A1:A10.

You could change this a little and use it in combination with the date to give you the summary you need.

=SUM(IF(FREQUENCY(MATCH(A1:A10,A1:A10,0),MATCH(A1:A10,A1:A10,0))>0,1))