sql查询

查询每一组数据的第二条记录

select A.*

from A csd
INNER JOIN
(
select max(id) as maxId, A from A t1
where id < (select max(id) from B t2 where t1.c = t2.c) group by c
) csd2 on csd.id = csd2.maxId and csd.c = csd2.c

where

csd.c = 421