i have a table services has this field serviceid (p.k) servicename
and i have table subscriber with field subscriberid (p.k) subscibername
and table subscription with field subscriptionid (p.k) serviceid (f.k) subscriberid (f.k) startdate enddate
the user can subscriber to any service in any day of the month and subscription period is one month !! user A subscribe to service A start date 5/9/2012 end date 5/10/2012
user B subscribe to service B start date 10/9/2012 end date 10/10/2012
so when user subscribe to a service he will automatically receive notification msg to his email
i want to add an automatically subscription... but i should add new field in subscription or what??
because in table of subscription i want to store each month who of users are subscribe to my service at last month ...
please if some one have another idea about subscription schema