Finding Unique Related Records

[ovrdrvn]

I have two tables: patients and visits. A layout in the visits table gives a sub-summary report of the kinds of visits and actions performed over a given period. I need to find the actual number or unique or distinct patients based on the found set of visits (as one patient could have been visited more than once in a period). A Summary field of the Count variety works in the patients table, but is useless in the visits table.

Help please! (for a good non-profit cause)

[ovrdrvn]

I've been tipped off to part of the answer after reading up on other posts: two variables where the first collects all of the IDs from the related or parent table; second variable is a counter. What I don't get is how to load the full set of IDs into the first field with some sort of delimieter and then how to loop through each and only up the ticker on the second variable fields if the ID is unique as there are sure to be dupes and we are only counting unique patients who've had care this year.