Who played on clay on 3 march 2012?
CREATE TABLE "futures_and_challengers_singles_titles" (
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent" text,
  "score" text
);
SELECT "opponent" FROM "futures_and_challengers_singles_titles" WHERE "surface"='clay' AND "date"='3 march 2012';