Oracle消除重复记录的几种方式

select distinct(empno) from emp

select e.* from emp e where e.rowid = (select max(e.rowid) from emp e 

delete e.* from emp e where e.rowid < (select max(e.rowid) from emp e

select deptno from emp group by deptno;

select d.id,d.outer_code from  dict_depts_source d order by outer_code

select d.id,d.outer_code,row_number() over(partition by outer_code order by outer_code) row_flag from  dict_depts_source d

delete from dict_depts_source where id in(
select id from(select d.id,d.outer_code,row_number() over(partition by outer_code order by outer_code) row_flag from  dict_depts_source d)t
where t.row_flag > 1)

select d.id,d.outer_code,row_number() over(partition by outer_code order by outer_code) row_flag from  dict_depts_source d