Oracle SQL使用for循环删除重复项

Question

I was asked to do a query to remove all duplicates that involve these 6 fields as we want a unique key in this table.

I need to leave the one with biggest ID on the table and delete all the other ones. I came up with the following code following the suggestion of using a for-loop to do it.

begin
  for rec in (
      select max(id), attribute, product, partner, pr_group, contact_person, branch, count(1) cnt
        from co_attribute
        where attribute = 100000034 and product = 100252046
        group by attribute, product, partner, pr_group, contact_person, branch
        having count(1) > 1
  ) loop
      delete from co_attribute
        where (attribute = rec.attribute
          or (attribute is null and rec.attribute is null))
          and (product = rec.product 
            or (product is null and rec.product is null))
          and (partner = rec.partner 
            or(partner is null and rec.partner is null))
          and (pr_group = rec.pr_group 
            or(pr_group is null and rec.pr_group is null))
          and (contact_person = rec.contact_person 
            or(contact_person is null and rec.contact_person is null))
          and (branch = rec.branch 
            or(branch is null and rec.branch is null))
          and (max(id) < rec.id)
          ;
      dbms_output.put_line(
  'Deleting duplicates '            || 
  ' |attribute: '    || rec.attribute     || 
  ', product: '      || rec.product     ||
  ', partner: '      || rec.partner     ||
  ', pr_group: '     || rec.pr_group    ||
  ', contact_person: ' || rec.contact_person  ||
  ', branch: '     || rec.branch        ||
  ', id: '       || rec.id          ||
  ', deleting row: '   || sql%rowcount
  );
  end loop;
end;
/

The where in the select is just so I don't mess up the entire DB while testing this script. This gives me the following errors:

Error report -
ORA-06550: line 22, column 15:
PL/SQL: ORA-00934: group function is not allowed here
ORA-06550: line 9, column 7:
PL/SQL: SQL Statement ignored
06550. 00000 -  "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.
*Action:

So I have two questions: first is, how do I solve this issue and is this the most effective way?

edit: removed the id field inside group by

Answer 1

You may use below statement to leave the one with biggest ID on the table and delete all the other ones :

delete co_attribute a
 where
   a.id <
   any (select b.id
          from co_attribute b
         where (a.attribute = b.attribute or (a.attribute is null and b.attribute is null))
           and (a.product = b.product or (a.product is null and b.product is null))
           and (a.partner = b.partner or (a.partner is null and b.partner is null))
           and (a.pr_group = b.pr_group or (a.pr_group is null and b.pr_group is null))
           and (a.contact_person = b.contact_person or (a.contact_person is null and b.contact_person is null))
           and (a.branch = b.branch or (a.branch is null and b.branch is null))
        );

Answer 2

I fixed it following a part of the comments and a few changes suggested over here! First I changed max(id) to max(id) maxid and also max(id) < rec.id to id < rec.maxid since maxid is part of rec and not of the delete query!

Thanks a lot for the help!