I am creating a game where I am calculating the user points on the basis of user activities. Everything is working fine - I got the sum of points and on the basis of points I calculated the rank. I have two columns for points calculation:
pointsup (contains up points) and
pointsdown (contains down points)
select sum(pointsup - pointsdown) as points from table1 t1 join table2 t2 on t2.Id = t1.id where t1.ActivityTime BETWEEN '2015-01-01' AND '2016-01-01' group by t1.id order by points desc
Everything is fine, but the problem comes when I have to rank the users with same points. In this case, I have to consider the registration date: who registers first will come up first on the ranking. The registration date is in another table
table3. I have tried to join this third table but the sum is behaving oddly, showing wrong sum calculation.
Can anyone help please?