Oracle中删除重复记录行

主要是利用oracle中记录行的rowid唯一。

去除重复记录（注意多次执行直到影响记录为0行）

delete from WBH_TEMP2 where terminal_id in (
select terminal_id from WBH_TEMP2 group by terminal_id having count(*)>1)
and rowid in (select max(rowid) from WBH_TEMP2 group by terminal_id having count(*)>1)

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与上面一条等价，这条执行一次即可去除重复记录

delete from WBH_TEMP2 where terminal_id in (
select terminal_id from WBH_TEMP2 group by terminal_id having count(*)>1)
and rowid not in (select min(rowid) from WBH_TEMP2 group by terminal_id having count(*)>1)

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大量数据的时候建议用CTAS

create table WBH_TEMP3 as select terminal_id from WBH_TEMP2 group by terminal_id

这样子WBH_TEMP3中就是去除重复的记录了。