求将命令整合起来

city tower_name tower_no TCH call_time hcall_time am daytime

宜州 宜州德胜都围A HA10131 14 24.6 0.52 非城区 2007-11-1
宜州 宜州德胜都围B HA10132 6 29.05 42.27 非城区 2007-11-1
宜州 宜州德胜都围A HA10131 14 56.57 55.19 非城区 2007-12-1
宜州 宜州德胜都围B HA10132 6 9.54 30.08 非城区 2007-12-1
宜州 宜州德胜都围C HA10133 13 26.85 73.09 非城区 2007-12-1
宜州 宜州怀远罗山A HA10161 14 24.07 0.32 非城区 2007-12-1
宜州 宜州怀远罗山B HA10162 13 24.25 57.97 非城区 2007-12-1
宜州 宜州怀远罗山C HA10163 13 27.31 63.84 非城区 2007-12-1
宜州 宜州福龙京口A HA10211 6 6.16 0.16 非城区 2007-12-1

用命令 select top 10 a.city,a.tower_name,a.tower_no,sum(a.total) as ctime
from(select city,tower_name,tower_no,daytime,(call_time+hcall_time) as total from master
where daytime>'2007-12-1' and daytime<'2007-12-7') a where a.city ='河池' group by a.city,a.tower_name,a.tower_no order by ctime DESC;显示

河池九龙C HC30123 3301 河池
河池中行B HC30052 3223 河池
河池公路宾馆C HC30073 3209 河池
河池公路宾馆A HC30071 3161 河池
河池局九楼C HC30023 2994 河池
河池河北派出所B HC30282 2977 河池
河池职大C HC30133 2915 河池
河池无委A HC30031 2764 河池

现在想将小区合起来，（即宜州德胜都围A，宜州德胜都围B，宜州德胜都围C合起来成为宜州德胜都围，然后将3条合并成一条，显示tower_name 和总话务（A，B，C三个小区的和）就可以了）然后再排序，已在另一帖求得合并A，B，C的语句
select tower_name = case when right(tower_name,1) between 'A' and 'Z' then left(tower_name,len(tower_name)-1) else tower_name end,
sum(call_time)call_time,
sum(hcall_time) hcall_time
from master
group by case when right(tower_name,1) between 'A' and 'Z' then left(tower_name,len(tower_name)-1) else tower_name end
但是怎么整合都报错，求高人指点，给出合起来的语句！