Del duplicate with different condition in a table.

Question

Hi All,
In my table, there are duplicate records. I need to delete duplicate records based on below 3 conditions.
Table : ABC
===========
DEPTID
DEPTNAME
Here, we identify whether records are duplicate or not based on DEPTID, but we need to consider DEPTNAME while deleting.
Conditions: 1
=============
Lets say, there are 3 records for DEPTID = 200, out of that, one record contains DEPTNAME and remaining 2 records are NULL, then remove records with DEPTNAME null and keep one with DEPTNAME.
Condition: 2
============
Lets say, out of 4 records (duplicate with DEPTID 200), 2 records have DEPTNAME and 2 records have DEPTNAME NULL, keep any one records which have DEPTNAME and remove remaining 3 records.
Condition: 3
============
Lets say, all 5 records (duplicate with DEPTID 200), have DEPTNAME NULL. Keep only 1 record and delete remaining duplicate.
Can someone help me how to achive this?

Answer 1

DELETE FROM abc
      WHERE ROWID NOT IN (
               SELECT r
                 FROM (SELECT ROWID r, deptid, deptname,
                              ROW_NUMBER () OVER (PARTITION BY deptid ORDER BY deptname DESC NULLS LAST)
                                                                           rn
                         FROM abc)
                WHERE rn = 1)Regards,
Mahesh Kaila