ORA-01440 要減小精度或者標度.則要修改的列必須為空.

　

　

--1 創建備份表
drop table contract_kangjia_back;
create table contract_kangjia_back
as 
select *　from contract_kangjia;
--2 將原有表的數據刪除
delete from contract_kangjia;
--3 改變原有表的數據結構
alter table contract_kangjia modify sell_money  number(10,5) ;
--4 將原有表的數據插入新的表
insert into contract_kangjia
  (id, busiman_name, sell_date, product_type, sell_money)
  select  id, busiman_name, sell_date, product_type, sell_money 
    from contract_kangjia_back;