CREATE TABLE "doubles_7_6_1" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "partner" text,
  "opponents_in_the_final" text,
  "score" text
);

Question: Who played on a hard surface?
SQL: SELECT "partner" FROM "doubles_7_6_1" WHERE "surface"='hard';