Need Oracle code logic

Question

i have a single row sub query which returns row with del_flag as N. Now in my db, there are 2 rows getting added from the incoming feed with del_flag as Y & N.
So how can i modify the query to return the row with del_flag as N. if there is no row with del_flag as N, it should return the row with del_flag as Y.
Could some one help me on this.

Answer 1

Try this:
SQL> select * from tab;
      ID_1 DEL_F       ID_3
         1 Y             10
         1 N             11
         2 Y              5
         3 N              6
SQL> SELECT id_1,
       MIN(CASE
             WHEN del_flag = 'N' THEN del_flag
             WHEN del_flag = 'Y' THEN del_flag
           END) del_flag,
       MIN(CASE
             WHEN del_flag = 'N' THEN id_3
             WHEN del_flag = 'Y' THEN id_3
           END) id_3
FROM   tab
GROUP  BY id_1 
      ID_1 DEL_F       ID_3
         1 N             10
         2 Y              5
         3 N              6