Post foreign key
Is there a way to include (as a session variable or something) and post the id from one table into another table as a foreign key. I have a two level registration process I'd like to use for a conference: one registration is the "User" and the other is for one or more "Participants" the User might register. Each Participant could be signed up for several "Activities". What I want to have happen is for the User to be able to register a Participant and then be able to sign him/her up for the activities, so I'd like the User ID ("id") to pass into the Registrant table (where the primary key would be "b-id") as "id" and still have the b-id auto increment.
These two IDs would also then pass into the "Orders" table (where the "o-id" would auto increment) as foreign keys along with a-id from the Activities table, etc.
Does nay of this make sense?