sqlserver row_num()的用法

select row_number() over(order by 表名 desc) as RowNumber_ID,*from 
(
   select t.name as '表名' ,i.name as '主键' 
   ,s.avg_fragmentation_in_percent as '阈值' from sys.tables t 
	join sys.indexes i on i.object_id=t.object_id  
	join sys.dm_db_index_physical_stats(db_id(),object_id(0),null,null,'limited') s  
	on s.object_id=i.object_id and s.index_id=i.index_id 
)
c

select row_number() over( partition by 阈值 order by 表名 desc) as RowNumber_ID,*from 
(
   select t.name as '表名' ,i.name as '主键' 
   ,s.avg_fragmentation_in_percent as '阈值' from sys.tables t 
	join sys.indexes i on i.object_id=t.object_id  
	join sys.dm_db_index_physical_stats(db_id(),object_id(0),null,null,'limited') s  
	on s.object_id=i.object_id and s.index_id=i.index_id 
)
c