CREATE OR REPLACE TRIGGER trig_obn_fam AFTER UPDATE ON ZP_STUDENTS FOR EACH ROW
   BEGIN
  IF :NEW.FAM<>:OLD.FAM THEN 
    DECLARE
      tabn1 ZP_STUDENTS.TABN%TYPE;
      CURSOR c1 IS SELECT zs.TABN FROM ZP_STUDENTS zs WHERE zs.FAM=:NEW.FAM;
      BEGIN
      OPEN c1;
      LOOP FETCH c1 INTO tabn1;  
	    EXIT WHEN c1%NOTFOUND;
      END LOOP;
      CLOSE c1;
      COMMIT;
    INSERT INTO ZP_FAMILIYA (
  KOD, TABN, ST_FAM, NOV_FAM, DATA_SMENY
)
VALUES (TRIG_SEQ.NEXTVAL, tabn1, :NEW.FAM, :OLD.FAM, SYSDATE);
    END;
END IF;
END;