I have this
person table as super parent,
id firstname lastname email telephone ... ...
user table as a child
id person_id (FK) password username screenname ... ...
They must be 1:1 relationship, because an user cannot be repeated twice. and so the email in the person row must not be repeated twice.
Then I have this
message table which stores messages from anyone,
id firstname lastname email telephone subject content ... ...
but you can see that
firstname,lastname, email,telephone are duplicated in
so I am thinking to refer it to
person table like this below,
id person_id subject content ...
but then it does not seem right, as a person with the same email, name, etc can send message to me as many times as they want. so the details he/she provides can be repeated.
so should I make
message as a child of
person the parent or they should be separate entities?
or any better suggestions to solve this problem.