Name the opponent for 12 may 2008
CREATE TABLE "league" (
  "match" real,
  "date" text,
  "opponent" text,
  "venue" text,
  "result" text,
  "turbine_goals" text,
  "attendance" real,
  "report" text
);
SELECT "opponent" FROM "league" WHERE "date"='12 May 2008';