数据库结构-两张表还是一张表？

Question

I have one database table dealing with users login totals and another table dealing with individual login sessions. Should I keep these tables separate or should I go ahead and merge them?

users_logins
    users_id
    successful_logins(total)
    last_online

users_logins_sessions
    users_id
    session_id
    ip_address
    user_agent
    last_activity(time-stamp)

Answer 1

This really depends on you, however I understand it as (making assumption here) that sessions are cleared? Typically in my applications sessions expire, and a new one is created, I am not sure how you manage that in your users_logins_sessions as you don't give much more info on this, it could work either way.

You should merge if your 'session' table never deletes entries, OR leave it alone the way it is, if the sessions expire / are deleted at intervals.

I am also assuming the users_id is used somewhere else if you keep them separate.

Answer 2

You could lose user_logins, as I assume last_online and last_activity contain same value.

You would however have to query the user_logins_sessions table to get the total for successful logins for a given user.

SELECT COUNT(user_id) FROM user_login_sessions WHERE user_id = ?

Answer 3

If you only have the users_logins_sessions table, you can easily query for successful_logins and last_online.

SELECT COUNT(1) AS successful_logins 
    FROM users_logins_sessions 
    WHERE users_id = <user_id>;

SELECT MAX(last_activity) AS last_online 
    FROM users_logins_sessions 
    WHERE users_id = <user_id>;