This may be easy for you, but here is my case. I have a table of customers and related table, called customers_portal. They all share same customer ID and in that portal I have customers' sales process information, like dates of meetings, time, info and to-do for the next meeting.
I have two date fields: 1) date of meeting 2) date of becoming a customer. I want to calculate on which meeting a person became a customer. So, basically, when a person becomes a customer, those two date fields show exact same date.
How do I do this?