Oracle PL/SQL Tutorial/Trigger/IS DROP COLUMN

IS_DROP_COLUMN

SQL> CREATE OR REPLACE TRIGGER what_got_dropped
  2  AFTER ALTER ON SCHEMA
  3  BEGIN
  4    IF IS_DROP_COLUMN("COL2") THEN
  5      DBMS_OUTPUT.PUT_LINE("You dropped col2");
  6    END IF;
  7  END;
  8  /
Trigger created.
SQL>
SQL> drop trigger what_got_dropped;
Trigger dropped.