oracle分组取每组第一条数据

oracle分组后取每组第一条数据

 

‘数据格式

 

 

分组取第一条的效果

 

 

[sql]
SELECT *        
   FROM (SELECT ROW_NUMBER() OVER(PARTITION BY x ORDER BY y DESC) rn,        
         test1.*        
         FROM test1)        
  WHERE rn = 1  ;