How to track that a user visited the site each day for X days?

Question

There is a new badge on Stack Overflow. The \"woot\" badge is awarded to users visited the site each day for 30 days. How can you implement a feature like this? How can you trac

Answer 1

Actually, if the Member's visits are in a SQL database, you can do the whole thing with a single SQL query. This is also probably faster than schlepping all of the data over to a client program to check it anyway:

/*
    Find all members who visited at least once every day
  for 30 or more days.  --RBarryYoung, 2009-05-31
*/
;WITH
  cteVisitDays as (
    Select
      MemberID
    , DATEDIFF(dd,'2008-06-01',VisitTime) as VisitDay
     From tblMembersLog
     Where Not Exists( Select * From tblMemberTags T
    Where T.MemberID = tblMembersLog.MemberID
     And T.TagName = 'WOOT!' )
     Group By MemberID
        , DATEDIFF(dd,'2008-06-01',VisitTime)
    )
, cteVisitRunGroups as (
    Select 
      MemberID
    , VisitDay - Row_Number() Over(
            Partition By MemberID
            Order By VisitDay
        ) as RunGrouping
     From cteVisitDays
     )
SELECT Distinct
  MemberID
 From cteVistRunGroups
 Group By MemberId, RunGrouping
 Having COUNT(*) >= 30