oracle查询不重复数据详解数据库

方法一：

select jqbh,cjdbh,sjybh,sjyxm

from (select t.jqbh,t.cjdbh,t.sjybh,t.sjyxm,row_number() OVER(PARTITION BY t.sjybh ORDER BY t.jqbh) ds from T_ITMP_TCS_DISPOSAL t

where t.sjyxm is not null)

where ds=1

 方法二：

select jqbh,cjdbh,sjybh,sjyxm

from T_ITMP_TCS_DISPOSAL

where cjdbh in(select min(cjdbh) from T_ITMP_TCS_DISPOSAL WHERE sjyxm is not null group by sjybh);

结果集：

参考：

—去重查询方法一:根据id

select * from sxe where id in(select min(id) from sxe group by username) order by id asc;

—去重查询方法二：根据rownum

select * from (select s.*,rownum rn from sxe s ) x where x.rn in (select min(rownum) from sxe group by username) order by id asc;

—去重查询方法三：根据rowid

select * from (select s.*,rowid rid from sxe s) x where x.rid in (select min(rowid) from sxe group by username) order by id asc;

select s.*,rowid from sxe s where rowid in (select min(rowid) from sxe group by username) order by id asc;

—去重删除方法一：根据ID

delete from sxe where id not in (select min(id) from sxe group by username);

—去重删除方法二：根据rownum

–delete from (select s.*,rownum from sxe s) x where rownum not in (select min(rownum) from sxe group by username);

—去重删除方法三：根据rowid

delete from sxe where rowid not in (select min(rowid) from sxe group by username);

备注：补充

oracle 进行数据增删改查一定要进行事务处理，7个事务处理。若发现数据无法进行更新操作，那么一定是没有进行事务处理。则解决方法为解锁oracle，方法如下：
SELECT object_name, machine, s.sid, s.serial#
FROM gv$locked_object l, dba_objects o, gv$session s
WHERE l.object_id　= o.object_id
AND l.session_id = s.sid;

alter system kill session ‘sid, serial#’;
ALTER system kill session ‘180, 60715’;