declare @T table (userid int,truename varchar(5))
insert into @T
select null,null union all
select 0,'员工1' union all
select 0,'员工2' union all
select 1,'张三' union all
select 1,'张三' union all
select 2,'李四'

select 
case when userid=0 then '一般' else isnull(truename,'特殊') end as truename,
count(1) as countnum 
from @t group by 
case when userid=0 then '一般' else isnull(truename,'特殊') END
/*
truename countnum
-------- -----------
李四       1
特殊       1
一般       2
张三       2
*/