Error in Trigger (PL/SQL: SQL Statement Ignored)

Question

Here is the trigger:
CREATE OR REPLACE TRIGGER DRUGREPLACEMENT
AFTER INSERT ON PHARMACEUTICALS
REFERENCING NEW AS newDrugs
FOR EACH ROW
WHEN (newDrugs.drugname = newDrugs.genericname)
BEGIN
UPDATE prescription
SET pharmaceuticalid = newDrugs.drugID
WHERE pharmaceuticalid IN(SELECT pharmaceuticalid FROM prescription, pharmaceuticals WHERE drugid = pharmaceuticalid AND newDrugs.genericname = pharmaceutical.genericname);
END;
Error is:
Error(2,1): PL/SQL: SQL Statement ignored
Error(3,24): PL/SQL: ORA-00904: "NEWDRUGS"."DRUGID": invalid identifier
pharmaceuticalid is a number in my prescription table.
drugid is a number; genericname and drugname are both varchars in my pharmaceuticals table. Any idea why I am getting these errors? (I tried putting quotes around newdrugs.drugid but then it just said "newdrugs.drugid" is invalid. Thanks for your help
-Brian

Answer 1

One more thing. Your trigger is selecting from triggering table. So single row inserts will work, but multiple row inserts into PHARMACEUTICALS will fail with famous "table is mutating" error. There is no need to select from PHARMACEUTICALS. Change:
UPDATE ************
SET pharmaceuticalid = newDrugs.drugID
WHERE pharmaceuticalid IN(SELECT pharmaceuticalid FROM ************, pharmaceuticals WHERE drugid = pharmaceuticalid AND newDrugs.genericname = pharmaceutical.genericname);to
UPDATE ************
  SET pharmaceuticalid = newDrugs.drugID
  WHERE pharmaceuticalid IN (
                             SELECT pharmaceuticalid
                               FROM ************
                               WHERE drugid = :newDrugs.pharmaceuticalid
                                 AND :newDrugs.genericname = pharmaceutical.genericname
                            );SY.