求一条简单的语句！该如何处理_Sql Server

求一条简单的语句！！
table1表(字段a1,字段a2,字段a3)
求一条语句，得到下面的结果集：
N SUM
---------------
N1 sum(a1)
N2 sum(a2)
N3 sum(a3)

//N1，N2，N3为任意标识

即得到上面三条数据，求解！

------解决方案--------------------

SQL code

select 'N1' as Col,sum(a1) from table1union allselect 'N2' as Col,sum(a2) from table1union allselect 'N3' as Col,sum(a3) from table1
------解决方案--------------------
select 'N1',sum(a1) union all
select 'N2',sum(a2) union all
select 'N3',sum(a3)
------解决方案--------------------
SQL codeselect 'N1' as N,sum(a1) AS [SUM] from table1union allselect 'N2' as N,sum(a2) from table1union allselect 'N3' as N,sum(a3) from table1--orSELECT *FROM (SELECT SUM(a1) AS N1,SUM(a2) AS N2,SUM(a3) AS N3) AS aPIVOT ([Sum] FOR N IN(N1,N2,N3)) AS b
------解决方案--------------------
探讨

楼上的，哪个最好呀？

------解决方案--------------------
探讨
楼上的，哪个最好呀？

------解决方案--------------------
探讨

引用:
楼上的，哪个最好呀？

CTRL+L查看查询计划。

------解决方案--------------------
SQL codeselect N='N1',[sum]=sum(a1) from table1union allselect 'N2',sum(a2) from table1union allselect 'N3',sum(a3) from table1