Percentage of appointments based on LASTDATE

[sherwood]

I'm trying to calculate the percentage of customers who have made an appointment, against the total number of customers. 
Unfortunately, as customers can make multiple appointments, the current total number of appointments exceeds the total number of customers. 

TOTAL Customer name	TOTAL Appointment Date
74	103

Is there a calculation I can do to create a measure based on a COUNT of LASTDATE without including the duplicate entries?
I've attached sample data below.

Table1	Table2	Table2
Customer name	Appointment Date	Last Appointment Date
A	27/10/2022	29/10/2022
A	28/10/2022	29/10/2022
A	29/10/2022	29/10/2022
B	30/10/2022	31/10/2022
B	31/10/2022	31/10/2022
C	01/11/2022	03/11/2022
C	02/11/2022	03/11/2022
C	03/11/2022	03/11/2022
D	04/11/2022	04/11/2022
E	05/11/2022	05/11/2022
F	06/11/2022	06/11/2022
G	07/11/2022	07/11/2022
H	08/11/2022	08/11/2022

[tamerj1]

Hi @sherwood 

How are you planning to disply the result? In card visual? Can you present an example?

[sherwood]

Hi,

I'd like to add a column that indicates if a Customer has made and Appointment, then show the Total as a percentage in a visual. 

[tamerj1]

@sherwood 

Add a column to what? To show the percentage in which type of visual? Can provide the screenshot? The Last Appointment Date is Column or a measure?

[sherwood]

Sorry, I was confusing two possible solutions. 

I need to get the total count of all Customers who have made an Appointment. I want to add the percentage to a table or card.

[tamerj1]

@sherwood 

The solution provided by @johnt75 shall provide the correct results 

[johnt75 · Accepted solution]

You can do something like

Customers with appointments = COUNTROWS(VALUES('Appointments'[Customer]))

[sherwood]

Apologies, it took some customising but this was the solution. Thank you for your help. 

[sherwood]

Hi, 

This seems to be counting all rows with appointment values, rather than accounting for last appointment date only. 

[eliasayy]

Hello please try:

Calculate(distinctcount([customer name]),filter(table,[last date] = max([last date]))

[sherwood]

Hi,

This is counting rows where there is no appointment date.