I’m having a table similar to this: first last date pos john doe 18-03-2021 harris potter 10-06-2021 john doe 10-05-2021 harris potter 14-06-2021 jessica potter 14-06-2021 kermit foster The use case is as follow: The pos column correspond to a positive covid test The date column correspond to the vaccination date To be elligible for a covid certificate, some one