Is the Community system logging successful logins and where can see that data?
I have found this:
SELECT [intID] ,[intObjectID] ,[intObjectTypeID] ,[strIP] ,[intUserID] ,[datCreated] ,[intAction] FROM tblEPiServerCommonActivityLog where intObjectID = 1940 and intObjectTypeID = 1 order by datCreated desc
In the above table I have found that intObjectTypeID in my case i IUser, but I would like to know how to interprete intAction, 1 seems to be "user created" but does 2 mean "user logged in"?
No, it's the same set of actions for all types of entities, I believe 2 is "update".
Also see http://sdk.episerver.com/community/4.1/html/T_EPiServer_Common_Logging_ActivityLogType.htm
If you are running a site configured to use the membership integration system to import users from another provider into the "native" common/community user system, I suppose an update may happen at the point of successful login. But even then not all updates of user entities are the result of logins.
OK, thanks! I have tested that I get a new "update" log row when logging in to this community for different users. I'm fairly certain that there aren't that many actions other users can take to update another IUser. Like you say I probably have all the logins here but also other save-actions.