Question

I need to find users that received bonus at my DB. The only users that interest to me, are those who got bonus more than one time.

How should I work this query to get ONLY users who got bonus more than once?

select Bonus, BonusUser, BonusType, Amount 
from Bonus 
where BonusType="1" 
order by BonusUser asc;

I need a query that prompts all “duplicated” rows, so I can remove bonus from them.

I haven’t explained before, but some users exploited a bug and could get free bonus, so I must select those duplicated rows, analyze and remove if it’s abuse case.

Answer 1

Add a GROUP BY and a HAVING clause

SELECT Bonus
    , BonusUser
    , BonusType
    , Ammount 
FROM Bonus 
WHERE BonusType="1" 
GROUP BY BonusUser
HAVING Count(*) > 1
ORDER BY BonusUser asc;

Based on your comment, I think this is what you want, this will give you the list of all users with a bonus but it will give you the count of those who had more than one bonus:

SELECT Bonus
    , t.BonusUser
    , BonusType
    , amount 
    , t2.cntbonus
FROM Bonus t
inner join 
(
    select count(*) as CntBonus, bonususer
    from Bonus
    where BonusType='1'
    group by bonususer
) t2
    on t.bonususer = t2.bonususer
WHERE BonusType='1'
ORDER BY BonusUser asc