select count(distinct 订单编号),sum(金额)

发现好用的东西

之前都傻傻的,先distinct出来,再count.
select count(*) from (select distinct 订单编号 from #订单)a

发现可以这样写,真是太方便了.
select count(distinct 订单编号)
from #订单

而且还可以同时把金额sum出来.
select count(distinct 订单编号),sum(金额)
from #订单

drop table #订单 create table #订单(订单编号 int,金额 int)insert into #订单  select 1,200insert into #订单  select 1,400insert into #订单  select 1,1400