SQL疑难有关问题!请问

SQL疑难问题!请教
'发贴统计
select poster as 用户名,count(*) as 发贴次数,sum(len(message)) as 发贴字数 From dnt_posts1 where fid = 7 and layer = 0 and postdatetime >= #02/01/2010# group by poster

'回贴统计
select poster as 用户名,count(*) as 回贴次数,sum(len(message)) as 回贴字数 From dnt_posts1 where fid = 7 and layer = 1 and postdatetime >= #02/01/2010# group by poster

怎么能将其合并成一条： “用户名，发贴次数，发贴字数，回贴次数，回贴字数”。

数据库是ACCESS。


[解决办法]

SQL code

select poster as 用户名,    sum(iif(layer = 0,1,0)) as 发贴次数,sum(iif(layer = 0,len(message),0)) as 发贴字数     sum(iif(layer = 1,1,0)) as 回贴次数,sum(iif(layer = 1,len(message),0)) as 回贴字数 From dnt_posts1 where fid = 7 and postdatetime >= #02/01/2010# group by poster