把表中重复的数据删掉 保留一行 表的顺序自动更新！

create table orders
(
    company varchar(10),
    ordernumber int
)
insert into orders
select ‘IBM‘,4566 union all
select ‘JIS‘,4565 union all
select ‘JOINY‘,4544 union all
select ‘JOINY‘,4544 union all
select ‘JOINY‘,4544 union all
select ‘EWIRU‘,2321 union all
select ‘HUIJ‘,4561 union all
select ‘HUIJ‘,4561

;with cte as
(
    select
        ROW_NUMBER() over(partition by company,ordernumber order by company,ordernumber) as ro,
         company,ordernumber
    from orders
)
--删除重复数据
delete from cte where ro>1

--重新定义顺序:顺序规则自己定义了
update orders set ordernumber=1+ro from
(select
    ROW_NUMBER() over(order by company,ordernumber) as ro
from orders) a