Question

I have a persons table with a name and id as well as a logs table with attributes who and what.
I want to insert into the logs table when I delete or insert into the persons table.

This is what I have so far:

CREATE OR REPLACE TRIGGER add_del
  BEFORE INSERT OR DELETE ON persons
  FOR EACH ROW
  BEGIN
    IF INSERTING THEN
      INSERT INTO logs (who, what) VALUES (name, 'Insert into persons');
    ELSE
      INSERT INTO logs (who, what) VALUES (name, 'Delete from persons');
    END IF;
  END;
  /

Why does this compile with the error:

Warning: Trigger created with compilation errors.

Answer 1

Since you didn’t post the error, I have to guess. My guess is that the problem is that name is not a valid identifier in this context. You need to reference either :new.name or :old.name. :old.name will be NULL on an insert while :new.name will be NULL on a delete so I’m assuming you want something like

CREATE OR REPLACE TRIGGER add_del
  BEFORE INSERT OR DELETE ON persons
  FOR EACH ROW
BEGIN
  IF INSERTING THEN
    INSERT INTO logs (who, what) VALUES (:new.name, 'Insert into persons');
  ELSE
    INSERT INTO logs (who, what) VALUES (:old.name, 'Delete from persons');
  END IF;
END;