what's the total number of singles w-l with doubles w-l of 0–0 and total w-l of 3–1
CREATE TABLE "squad_members" (
  "player" text,
  "years_played" text,
  "total_w_l" text,
  "singles_w_l" text,
  "doubles_w_l" text
);
SELECT COUNT("singles_w_l") FROM "squad_members" WHERE "doubles_w_l"='0–0' AND "total_w_l"='3–1';