Можете ли вы попробовать
SELECT Value, MXValue
FROM (
select sum(value) as 'Value',max(value) MXValue
from table_name
group by id_name
) as t1
order by value desc
LIMIT 0,1
Из MySQL Forums :: General :: selection MAX (SUM ())
Или вы можете попробовать что-то вроде
SELECT id_name,
Value
FROM (
select id_name,sum(value) as 'Value'
from table_name
group by id_name
) t
WHERE Value = (
SELECT TOP 1 SUM(Value) Mx
FROM table_name
GROUP BY id_name
ORDER BY SUM(Value) DESC
)
Или даже с внутренним соединением
SELECT id_name,
Value
FROM (
select id_name,sum(value) as Value
from table_name
group by id_name
) t INNER JOIN
(
SELECT TOP 1 SUM(Value) Mx
FROM table_name
GROUP BY id_name
ORDER BY SUM(Value) DESC
) m ON Value = Mx