Question

I’m looking for help with part of a database design.

I have to Model the Database for a Group of Contacts and a Group of Distribution Lists.

Each Contact can be in many Distribution Lists and each Distribution List can have many Contacts. In a normal Instance, I could use a Junction table to achieve this solution.

But there’s one more thing to add. Contacts have the option to receive notifications via two different methods which are SMS or Email.

A Contact can request to be sent notification via either or both methods.

The piece of the problem that I am stuck with, is that a Contact may wish to receive notifications differently depending on the specific distribution list.

So we have a problem like this :–

CONTACT A is in DL-A - Receives Notification via SMS 
CONTACT A is in DL-B - Recieves Notification via Email & SMS.

I’m trying to avoid having more than one entry for a Contact in my Contacts Table, each contact should be unique.

Can Anyone help?

Answer 1

So you can add to fields in the junction table:

ContactsDistributions(ContactId, DistributionId, SMSFlag, EmailFlag)

in order to specify the type of notification choosen by the contact for each distribution.