sql server 中的 row_number

代码

declare   @a   table (id  int  ,name  varchar ( 50 ))
insert   into   @a  (id,name)
select   ' 1 ' , ' a '
union   all
select   ' 1 ' , ' a '
union   all
select   ' 2 ' , ' n '
union   all
select   ' 2 ' , ' n '
union   all
select   ' 2 ' , ' n '
union   all
select   ' 3 ' , ' b '
union   all
select   ' 3 ' , ' b ' ;

with  b  as (
   SELECT  ROW_NUMBER()  OVER  ( PARTITION  BY  id,name  ORDER   BY  id)  AS  rcount, *   FROM   @a
)
select   *   from  b