How to count the number of patients once in a table

[sjenrette87]

I am trying to count the number of patients seen once in a table. I've read the forum and only found to do distinct count but it is counting the patient multiple times. I only want to count the patient once even though they were seen with multiple service date with multiple line items.

[Lisa_P]

You must count something that has unique values for each customer, can you show some sample data ?

[sjenrette87]

I am new to this platform so I am not sure how to show a preview. I am trying to count how many patients each provider treats! Any ideas how to create an expression, I am using the patient's medical records number count.