oracle表删除重复值，只保留一条重复数据

select * from T_model_grjcxx_00 a where rowid <(select max(b.rowid) from  T_model_grjcxx_00 b where a.khtybh=b.khtybh)




select a.khtybh ,a.cjrq from T_model_grjcxx_00 a  group by a.khtybh ,a.cjrq having count(*)>1;


delete  from T_model_grjcxx_00 a  group by a.khtybh ,a.cjrq having count(*)>1;

--删除重复值

保留rowid最大的数据

delete from  T_model_grjcxx_00 a   --表名

where 

(a.khtybh ,a.cjrq) in (select khtybh ,cjrq from T_model_grjcxx_00 group by khtybh ,cjrq having count(*)>1)  --查询主键行数大于1的

and rowid not in (select min(rowid) from T_model_grjcxx_00 group by  khtybh ,cjrq having count(*)>1) --筛选出rowid最小的数据，只保留rowid最大的一行数据