New to mysql, need some help

Ok so i have an invision power board. What I am trying to do is create a portfolio so that the members can have their own stock portfolios. I have the content streaming from redinews.com . What I need to do is add a table containing the stock information, which ive done. How would I go about making that table “talk” to the members table so that it knows which stock portfolio row belong to whoever is logged in? many thanks in advance :tie: