select * from abc a inner join ( SELECT max(id) id FROM abc group by a1 ) b on a.id=b.id
select * from abc where id in (select id from(select min(id) as id,a1 from abc group by a1))
select * from abc where id in (select id from(select min(id) as id,a1 from abc group by a1)) --------------------------------------- 多写个SELECT 干吗?? select * from abc where id in (select min(id) as id from abc group by a1)
select * from abc where not exists(select 1 from abc where a1>abc.a1)
inner join
(
SELECT max(id) id FROM abc
group by a1
) b on a.id=b.id
---------------------------------------
多写个SELECT 干吗??
select * from abc where id in (select min(id) as id from abc group by a1)