select test_id,test_time,test_count
from test a,
(select test_id,max(test_count) max_count from test group by test_id) b
where a.test_id=b.test_id and a.test_count=b.max_count;
from test a,
(select test_id,max(test_count) max_count from test group by test_id) b
where a.test_id=b.test_id and a.test_count=b.max_count;
from test where (test_id,test_count) in (select test_id,max(test_count) from test group by test_id)
from test
group by test_id, test_time