ALTER TABLE public.faq_items
    ADD COLUMN IF NOT EXISTS best_reply_id uuid;

DO $$
BEGIN
    IF NOT EXISTS (
        SELECT 1 FROM pg_constraint WHERE conname = 'faq_items_best_reply_id_fkey'
    ) THEN
        ALTER TABLE ONLY public.faq_items
            ADD CONSTRAINT faq_items_best_reply_id_fkey
            FOREIGN KEY (best_reply_id) REFERENCES public.faq_replies(id) ON DELETE SET NULL;
    END IF;
END $$;

CREATE INDEX IF NOT EXISTS ix_faq_items_best_reply_id ON public.faq_items USING btree (best_reply_id);