data base structure for a instant messenger application
I am working on a simple instant messenger application similar to yahoo but not as complicated as yahoo messenger. I am not a fine database designer. I am basically a newbie in these database stuffs. I have uploaded my database structure about how i am going to implement the system.
Please guide me in finding the faults, drawbacks of the structure.
what might be the drawbacks, what might be the problems, is this thing correct ?
The notation you are using is a little different than those I am familiar with, but I think buddy list should have two relationships to users. One for buddy_list.user_id and one for the aliased user, buddy_list.buddy_id.
well i also think the restricted thing is kinda baseless there.
what i am wanting to do is that "restricted" table just contains a list of user_id OR ip_addresses that are forbidden to use the system.
I also dont think that should be linked like because it is just a list.
when the admin wants to ban a user or an ip address he just updates or insert a record in the "restricted" column.
he can either put a user_id OR ip_address OR both in the "restricted"
Is there anyway i can express that in the diagram ? (i think the way i am doing it there is completly baseless. please guide me if i can actually show it in the diagram or is it that i dont have to show it and leave it as just a 3rd table that isnt in the diagram ?)