List the lowest super league for a 0 champion league.
CREATE TABLE "top_assistants" (
  "position" text,
  "number" real,
  "player" text,
  "super_league" real,
  "champions_league" real,
  "swiss_cup" real,
  "total" real
);
SELECT MIN("super_league") FROM "top_assistants" WHERE "champions_league"=0;