What is the format of code 9 40231-2 (us only)?
CREATE TABLE "singles_and_e_ps" (
  "title" text,
  "release_date" text,
  "format" text,
  "code" text,
  "uk_singles_chart" text,
  "us_modern_rock" text,
  "album" text
);
SELECT "format" FROM "singles_and_e_ps" WHERE "code"='9 40231-2 (us only)';