Oracle deletes duplicate data, leaving only one

Query and delete duplicate records SQL sentence

1、 Look up redundant duplicate records in the table , Duplicate records are based on a single field （Id） To judge

select * from  surface  where Id in (select Id from  surface  group byId having count(Id) > 1)

2、 Delete redundant duplicate records in the table , Duplicate records are based on a single field （Id） To judge , There is only rowid Minimum record

DELETE from  surface  WHERE (id) IN ( SELECT id FROM  surface  GROUP BY id HAVING COUNT(id) > 1) 
AND ROWID NOT IN (SELECT MIN(ROWID) FROM  surface  GROUP BY id HAVING COUNT(*) > 1);

3、 Look up redundant duplicate records in the table （ Multiple fields ）

select * from  surface  a where (a.Id,a.seq) in(select Id,seq from  surface  group by Id,seq having count(*) > 1)

4、 Delete redundant duplicate records in the table （ Multiple fields ）, There is only rowid Minimum record

delete from  surface  a where (a.Id,a.seq) in (select Id,seq from  surface  group by Id,seq having count(*) > 1)
and rowid not in (select min(rowid) from  surface  group by Id,seq having count(*)>1)

5、 Look up redundant duplicate records in the table （ Multiple fields ）, It doesn't contain rowid Minimum record

select * from  surface  a where (a.Id,a.seq) in (select Id,seq from  surface  group by Id,seq having count(*) > 1) 
and rowid not in (select min(rowid) from  surface  group by Id,seq having count(*)>1)