高手解决SQL语句中动态给WHERE条件解决方法

高手解决SQL语句中动态给WHERE条件
select distinct UserInfoID from HB_UserInfo order by UserInfoID
  
  select Sum(ReadCount) as readcount,HB_UserInfo.UserName from HB_Post, HB_UserInfo where HB_Post.UserInfoID='12'
  
  select UserName from HB_UserInfo where UserInfoID='12'

我要三句变一句 下面两句中的UserInfoID要改成遍历第一句中的结果集 动态给 比如：第一句结果集{1,2，3}，那下面2句中的UserInfoID为1,2,3；结果是3条记录 

有高手帮忙吗 


------解决方案--------------------
select Sum(ReadCount) as readcount,HB_UserInfo.UserName from HB_Post, HB_UserInfo where HB_Post.UserInfoID in(select distinct UserInfoID from HB_UserInfo order by UserInfoID)
 
select UserName from HB_UserInfo where UserInfoID in(select distinct UserInfoID from HB_UserInfo order by UserInfoID)
------解决方案--------------------

SQL code

select Sum(ReadCount) as readcount,HB_UserInfo.UserName from HB_Post, HB_UserInfo where HB_Post.UserInfoIDin(select distinct UserInfoID from HB_UserInfo)
------解决方案--------------------
select Sum(ReadCount) as readcount,HB_UserInfo.UserName from HB_Post, HB_UserInfo where HB_Post.UserInfoID
in(select distinct UserInfoID from HB_UserInfo)