oracle中怎么去掉某个字段重复数据库

Posted 2023-02-25

假如表 tb 有 id, name 两列，想去掉name中重复的，保留id最大的数据。
delete from tb a
where id not in (select max(id) from tb b where b.name=a.name)

若不是这个意思，那么说明的你意图。 参考技术A 1、有一个函数row_number() over(partition by ID order by message)
2、例如,msg_table，根据message重复值判断是否重复：
delete from msg_table where message_id in (select message_id from (select a.message_id,row_number() over(partition by message order by message) as n from msg_table a where id=20000 ) where n > 1); 参考技术B select *
from A,
(select max(id) id_m, 某个字段
from A
group by 某个字段) B
where A.id = B.id_m