database - strange MySQL join query results with aggregate functions -

i wrote following join query report using aggregate functions

select users.id, sum(orders.totalcost) bought, count(comment.id) commentscount, count(topics.id) topicscount, count(users_login.id) logincount, count(users_download.id) downloadscount  users  left join orders on users.id=orders.userid , orders.paystatus=1  left join comment on users.id=comment.userid  left join topics on users.id=topics.userid  left join users_login on users.id=users_login.userid  left join users_download on users.id=users_download.userid  group users.id order bought desc 

but don't know why following output?

the result of aggregate functions multiplied each other!!!

i don't know why?

for example last row expected following result

821    |    48000    |    63    |    0    |    10    |    10 

the result of executing explain query shown below

one reason type of result using left joins users table , result set may contains duplicate rows each user getting count more expected 1 can use distinct in count count unique associations per user , sum of totalcost can use subselect have sum each user without having repeated values orders of user

select    u.id,   coalesce(o.bought,0) bought   count(distinct c.id) commentscount,    count(distinct t.id) topicscount,    count(distinct ul.id) logincount,   count(distinct ud.id) downloadscount  users u left join (select             userid,            sum(totalcost) bought             orders             paystatus=1             group userid) o on u.id=o.userid left join `comment` c on u.id=c.userid  left join topics t on u.id=t.userid  left join users_login ul on u.id=ul.userid  left join users_download ud on u.id=ud.userid  group u.id order bought desc