Who entered on day 1 and exited on day 20?
CREATE TABLE "series_9_2009" (
  "celebrity" text,
  "famous_for" text,
  "entered" text,
  "exited" text,
  "finished" text
);
SELECT "celebrity" FROM "series_9_2009" WHERE "entered"='day 1' AND "exited"='day 20';