Which Effective date has a Where of illinois, and Affected area codes of 217?
CREATE TABLE "see_also" (
  "new_area_code" real,
  "where" text,
  "affected_area_codes" text,
  "format" text,
  "effective_date" text
);
SELECT "effective_date" FROM "see_also" WHERE "where"='illinois' AND "affected_area_codes"='217';