一下SQL语句有什么有关问题

一下SQL语句有什么问题？
select @[email protected]+Count(*)
  from (
select distinct(ProcessId)
from dbo.ProcessedInstance
where [email protected] and AcceptanceTime>@stime and AcceptanceTime<@etime
)

对sql不熟

------解决方案--------------------
select @[email protected]+Count(*)
from (
select distinct(ProcessId)
from dbo.ProcessedInstance
where [email protected] and AcceptanceTime>@stime and AcceptanceTime<@etime
) t
------解决方案--------------------

SQL code

select @[email protected]+Count(*)  from (select distinct(ProcessId)from dbo.ProcessedInstancewhere [email protected] and AcceptanceTime>@stime and AcceptanceTime<@etime) t你是吧你面的查询语句作为表来查询，所以得去个别名t