Question

I’m having problem with simple trigger command. This trigger operation will insert value into table address_rit when a person who studies at RIT is inserted into table person. Here’s the syntax for the trigger command:

CREATE OR REPLACE TRIGGER addr
AFTER INSERT ON person
FOR EACH ROW
WHEN (NEW.college = 'RIT')
BEGIN
INSERT INTO address_rit (name, address, state) 
VALUES (NEW.name, NEW.address, (SELECT name FROM states WHERE NEW.statecode = states.statecode));
END;
/

The trigger is compiled but with warning. However, further inspection shows that the trigger actually has error. Here’s the error from the compilation.

PL/SQL: SQL Statement ignored   ERROR
PL/SQL: ORA-00984: column not allowed here  ERROR

I’m pretty sure the error is just a syntax error, but I just can’t find any solution. Let me know if I need to add more detail. Thank you very much for your help.

Answer 1

At a minimum, you need a colon before NEW

CREATE OR REPLACE TRIGGER addr
  AFTER INSERT ON person
  FOR EACH ROW
  WHEN (NEW.college = 'RIT')
BEGIN
  INSERT INTO address_rit (name, address, state) 
    VALUES (:NEW.name, 
            :NEW.address, 
            (SELECT name 
               FROM states 
              WHERE :NEW.statecode = states.statecode));
END;
/

I’m also assuming that the query against the STATES table is always going to return exactly 1 row. If the database is properly normalized, though, I would expect that all the tables would have a STATECODE column rather than a STATE column and that there would be foreign keys between both PERSON and ADDRESS_RIT that reference the STATECODE column in STATES. But, if the database is properly normalized, I would also expect that you wouldn’t have an ADDRESS_RIT table that duplicated the data in PERSON. Instead, ADDRESS_RIT really ought to be a view on the PERSON table.