Question

My website allows users to record bids. Each bid is saved individually and associated to a user Id. A user can have many bids which are used to add up to one overall bid which is displayed upon the site.

What I am trying to do in sql is return the position a users overall bid is from a result set.

The sql I am using is below but problems arise when I use the group by command – the ordering seems to revert back to the default db order rather than by the sum of a users bid amounts:

SET @rowcount = 0;
SELECT rowCount, userId FROM (
    SELECT userId, @rowcount := @rowcount + 1 as rowCount, sum(amount) as amount FROM bids group by userId order by amount desc
 ) t when product = xxxxx

appreciate if anyone knows if this is possible?

Answer 1

You need to move rowcount incrementation out of subquery. And put your WHERE condition inside, otherwise your subquery will sum bids on all products for a given user.

SET @rowcount = 0;
SELECT @rowCount:=@rowcount+1 as rowcount, userId, amount FROM 
 (
    SELECT userId, sum(amount) as amount 
    FROM bids 
    WHERE product = xxxxx 
    GROUP BY userId 
    ORDER BY amount DESC
 ) t