ALTER TABLE organization_assets
  ADD COLUMN IF NOT EXISTS form_id integer,
  ADD COLUMN IF NOT EXISTS field_code varchar(100),
  ADD COLUMN IF NOT EXISTS field_value text;

DO $$
BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM pg_indexes
    WHERE indexname = 'organization_assets_form_field_idx'
  ) THEN
    CREATE INDEX organization_assets_form_field_idx
      ON organization_assets (form_id, field_code, field_value);
  END IF;
END $$;

ALTER TABLE organization_assets
  DROP CONSTRAINT IF EXISTS organization_assets_form_id_fkey;

ALTER TABLE organization_assets
  ADD CONSTRAINT organization_assets_form_id_fkey
  FOREIGN KEY (form_id) REFERENCES forms(id) ON DELETE SET NULL;