gistfile1.sql

CREATE FUNCTION wine_books_search_content_trigger() RETURNS trigger AS $$
begin
  new.search_content := (
    -- MUST use COALLESCE here if any of these columns can be NULL
    SELECT to_tsvector(COALESCE(wine_books.code, '') || ' ' || COALESCE(wine_books.name, '') || ' ' || COALESCE(producers.name, '') || ' ' || COALESCE(varietals.name, '') || COALESCE(wine_books.year::varchar, ''))
    FROM wine_books 
    LEFT OUTER JOIN producers ON producers.id = wine_books.producer_id
    LEFT OUTER JOIN varietals ON varietals.id = wine_books.varietal_id
    WHERE wine_books.id = new.id);
  return new;
end
$$ LANGUAGE plpgsql;

CREATE TRIGGER update_search_content BEFORE INSERT OR UPDATE
ON wine_books FOR EACH ROW EXECUTE PROCEDURE wine_books_search_content_trigger();