Which hard has a Clay of 0–0, Grass of 0–0,  Carpet of 0–0, and a Record of 1–0?
CREATE TABLE "head_to_head_record" (
  "record" text,
  "hard" text,
  "clay" text,
  "grass" text,
  "carpet" text
);
SELECT "hard" FROM "head_to_head_record" WHERE "clay"='0–0' AND "grass"='0–0' AND "carpet"='0–0' AND "record"='1–0';