筛选机台的维修次数最多的零件

筛选出机台id相同的零件中出现次数最多的结果   以MACHINE_ID分类

select * from (
select count(*) as num ,machine_id,device_id,device_name from tablename group by machine_id,device_id,device_name) b
where (b.num,machine_id) in(
select max(num),machine_id from (
select count(*) as num ,machine_id,device_id,device_name from tablename group by machine_id,device_id,device_name) a
group by machine_id
)