sql 分组查询 统计解决办法

sql 分组查询 统计

select COUNT(PrjInfo_ConstructionUnit),PrjInfo_ConstructionUnit from PRJ_PrjInfo

group by PrjInfo_ConstructionUnit

想在加一列，统计查询count列的总和，例如：
_count           PrjInfo_ConstructionUnit          _sum
10                     单位1                                            15
3                        单位2                                            15
2                       单位3                                              15

应该如何实现？
------解决思路----------------------

select COUNT(PrjInfo_ConstructionUnit),PrjInfo_ConstructionUnit

  ,(select  COUNT(PrjInfo_ConstructionUnit) from PRJ_PrjInfo ) [_sum]

from PRJ_PrjInfo

group by PrjInfo_ConstructionUnit

------解决思路----------------------
select COUNT(PrjInfo_ConstructionUnit),PrjInfo_ConstructionUnit ,(select COUNT(PrjInfo_ConstructionUnit) from PRJ_PrjInfo ) as [_sum]
 from  PRJ_PrjInfo  group by PrjInfo_ConstructionUnit 


------解决思路----------------------

select COUNT(PrjInfo_ConstructionUnit),PrjInfo_ConstructionUnit ,(select sum(PrjInfo_ConstructionUnit) from PRJ_PrjInfo)

as _sum from PRJ_PrjInfo group by PrjInfo_ConstructionUnit

------解决思路----------------------

引用:

select COUNT(PrjInfo_ConstructionUnit),PrjInfo_ConstructionUnit

	,COUNT(PrjInfo_ConstructionUnit)OVER()[_sum]

from PRJ_PrjInfo

group by PrjInfo_ConstructionUnit

SQL2005+

理解错了，好像只能用子查询了~~