Oracleɾ³ý±íÖÐÖظ´¼Ç¼

--刪³ýÖØ復ÁÐ  
  a.Èç¹ûÓÐID×ֶΣ¬¾ÍÊǾßÓÐΨһÐÔµÄ×ֶΠ 
   
  delect   table   where   id   not   in   (  
   
  select   max(id)   from   table   group   by   col1,col2,col3...  
  )  
  group   by   ×Ó¾äºó¸úµÄ×ֶξÍÊÇÄãÓõ½ÅÐ斷Öظ´µÄ×ֶΠ 
   
   
   
  b.,Èç¹ûÊÇÅÐ斷ËùÓÐ×ֶΠ 
  select   *   into   #aa   from   table   group   by   id1,id2,....  
  delete   table   table    
  insert   into   table    
  select   *   from   #aa  
   
   
   
  c.Èç¹û±íÖÐÓÐIDµÄÇé況  
   
  select   identity(int,1,1)   as   id,*   into   #temp   from   tabel  
  delect   #   where   id   not   in   (  
  select   max(id)   from   #   group   by   col1,col2,col3...)  
  delect   table  
  inset   into   table(...)  
  select   .....   from   #temp  
   
   
  col1+','+col2+','...col5   組ºÏÖ÷鍵  
   
   
  select   *   from   table   where   col1+','+col2+','...col5   in   (  
   
  select   max(col1+','+col2+','...col5)   from   table    
  where   having   count(*)>1  
  group   by   col1,col2,col3,col4    
  )  
  group   by   ×Ó¾äºó¸úµÄ×ֶξÍÊÇÄãÓõ½ÅÐ斷Öظ´µÄ×ֶΠ 
   
  d.