How to add multiple many many?

Nov 15, 2016 at 7:10 PM
I want to add multiple many to many relationships but I cant get it to work.

I have Periods who have Seasons, I update a Period and after that a I want tot delete very relation to Season and add the Seasons from the parameter.

How can I remove al the relations and then add ad list of relations?
Maybe someone can give a example?