Sql实现查找第二大的数据

一、不用考虑去重

select * from gatewaycase where rpid ORDER BY rpid desc limit 1,1
select * from gatewaycase where rpid ORDER BY rpid desc limit 1 offset 1

二、考虑去重

select MAX(rpid) from gatewaycase where rpid < (select MAX(rpid) from gatewaycase)

也可以使用top命令