删除重复行记录

delete  from  table_name  where  table_column  in (   
select  table_column  from table_name group by table_column having count(*)>1)   
and  rowid  in  (select max(rowid)  from  table_name  group  by  table_name  having count(*)>1)  


大量数据时：
create table  table_name2  as  select  table_column  from  table_name  group by table_column