CREATE TABLE "past_winners" (
  "year" real,
  "men_s_singles" text,
  "women_s_singles" text,
  "men_s_doubles" text,
  "women_s_doubles" text,
  "mixed_doubles" text
);

Question: what game had a doubles round in 1979
SQL: SELECT "mixed_doubles" FROM "past_winners" WHERE "year"=1979;