sql的delete删除和事务

一般都是 delete from table  where table.字段 = ...

如果table使用别名，则应该：

DELETE a from (
select *,ROW_NUMBER() over(PARTITION by empid order by empid) as rn from b_emp ) a where rn = 1 

这句话还包含了一个去重复的功能。

如果在sqlserver中使用增删改的功能，需要rollback或者commit的话，需要先开启事务。否则不在事务中的话 是不能rollback的

begin tran 
DELETE a from (
select *,ROW_NUMBER() over(PARTITION by empid order by empid) as rn from b_emp ) a where rn = 1  

rollback;

commit;