如何使存储过程根据另一个表中的行顺序更新一个表中的一列？

Question

I have two tables

Users:

user    |  name  |  country |  rank              | country_rank       | points
1       |  frank |  US      |  to be determined  | to be determined   | to be determined

Awards:

awarded_to  |  points_awarded  
1           |  10
1           |  30

How can I make a stored procedure to update the users total points based off of the points from awards , then their rank and country_rank respectively based off of the order of the points (ie rank 1 would be the user with the most points )?

I considered making a PHP script and using a crontab to call it occasionally that would just select the info and do the math etc in PHP, but stored procedures seems much more practical for my use-case.

Answer 1

create temporary table awardsum (user int, total int); #temp
insert into awardsum
select a.awarded_to, sum(a.points_awarded) 
from users u 
inner join awards a on u.user=a.awarded_to
group by a.awarded_to;

update users
join awardsum on users.user=awardsum.user
set users.points = awardsum.total;    

SELECT @row:=0;
UPDATE users
SET rank = (@row:=@row+1)
ORDER BY points desc;

drop table awardsum;