Oracle删除表中重复数据的方法

创建表用于测试：

删除表中的重复的数据，保存rowid最小的一个数据：

delete from tbl_a a
where 
       a.a_name in (select b.a_name from tbl_a b group by b.a_name having count(b.a_name)>1)
and 
       rowid not in (select min(rowid) from tbl_a c group by c.a_name having count(*)>1);

输出后的表：