Select * from sap_exc_rate
where exe_type in ('USD/RMB','JPY/RMB')
and EFF_DATE = (SELECT MAX(EFF_DATE) from sap_exc_rate)
//上面这么写必需的条件是:最新的两条数据在最新的日期中,而且必须是同一天有两个数据。
Select * form sap_exc_rate
where id in (
select top 1 id from sap_exc_rate
where EXC_RATE = 'USD/RMB' order by EFF_DATE desc
)
or id in (
select top 1 id from sap_exc_rate
where EXC_RATE = 'JPY/RMB' order by EFF_DATE desc
)
//这个可以实现不同的条件,即使31日USD为最新,29日JPY为最新同样能够实现