数据库设计：每位用户每天的价值

Question

I'm setting up a system where for every user (1000+), I want to add a set of values every single day.

Hypotetically: A system where I can log when Alice and Bob woke up and what they had for dinner on the August 1st 2019 or 2024.

Any suggestions on how to best structure the database tables?

A person table with a primary person ID? rows: n

A date table with a primary date ID? rows: m

And a personDate table the person ID and date ID as foreign keys? rows nxm

Answer 1

I don't think u need a date table unless u want to use it to make specific queries easier. Such as left join against the date to see what days you are missing events. Nevertheless, I would stick to the DATE or DATETIME as the field and avoid making a separate surrogate foreign key. It won't save any space and will potentially perform worse and will be more difficult to use for the developer.

This seems simple and fine to me. I wouldn't worry too much about the performance based upon the number of elements alone. You can insert a billion records with no problem and that implies a very large site.

Just don't insert records if the event didn't happen. In other words you want your database to grow in relation to the real usage. Avoid growth based upon phantom events and you should be okay.

person
    person_id


action
    action_id

personAction
    person_id
    action_id
    action_datetime