Question

I am trying to create a trigger but is having errors….

SQL> CREATE OR REPLACE TRIGGER INV_TOTAL
  2  BEFORE INSERT OR UPDATE ON INVOICE
  3  FOR EACH ROW
  4  BEGIN
  5     SELECT
  6        NVL((SELECT R.SUBTOTAL FROM HOLIDAY_RESERVATION R WHERE R.RESV_ID = :NEW.INV_ID), 0) +
  7       NVL((SELECT R.SUBTOTAL, (R.SUBTOTAL*20)/100 FROM HOLIDAY_RESERVATION R WHERE R.RESV_ID = :NEW.RESV_ID),0)
  8        INTO :NEW.INV_TOTAL_PRICE
  9     FROM DUAL;
 10  END;
 11  /

Warning: Trigger created with compilation errors.

SQL> SHOW ERRORS;
Errors for TRIGGER INV_TOTAL:

LINE/COL ERROR
-------- -----------------------------------------------------------------
2/4      PL/SQL: SQL Statement ignored
4/9      PL/SQL: ORA-00913: too many values
SQL>

Where is it finding too many values, all i want is select whats in field subtotal, add 20% and update a field in another table

Answer 1

The reason behind “Too many values” error is that in your select statements you do the following:

NVL((SELECT R.SUBTOTAL FROM HOLIDAY_RESERVATION R WHERE R.RESV_ID = :NEW.INV_ID), 0) ' 1 value
NVL((SELECT R.SUBTOTAL, (R.SUBTOTAL*20)/100 FROM HOLIDAY_RESERVATION R WHERE R.RESV_ID = :NEW.RESV_ID),0) ' gives 2 values (subtotal, subtotal*20 / 100)

Calling NVL with 2 values throws ORA-00913. Even if it didn’t, it’d throw eventually when you try to add 1 value with 2.

Also, I’d set fully qualified schema names beside every declaration.