create proc sp_top20
@starttime datetime,
@finishtime datetime
as
begin
select top 20 username,rtrim(count(username))+'篇' as 贴子数
from 发贴
where AddTime between @starttime and @finishtime
group by username
end
@starttime datetime,
@finishtime datetime
as
begin
select top 20 username,rtrim(count(username))+'篇' as 贴子数
from 发贴
where AddTime between @starttime and @finishtime
group by username
end
@starttime datetime,
@finishtime datetime
as
begin
select top 20 username,rtrim(count(username))+'篇' as 贴子数
from 发贴
where AddTime between @starttime and @finishtime
group by username
order by count(username) desc
end
怎么才能合理地建索引
比如说我只在userid上建立,并没有在username上建立
哪又该如何呢?
@starttime datetime,
@finishtime datetime
as
begin
select top 20 username,rtrim(count(userid))+'篇' as 贴子数
from 发贴
where AddTime between @starttime and @finishtime
group by username
end