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

Question: Who all played mixed doubles in 2010?
SQL: SELECT "mixed_doubles" FROM "previous_winners" WHERE "year"=2010;

Question: Who played women's singles in the year after 2006 when men's singles was cancelled?
SQL: SELECT "women_s_singles" FROM "previous_winners" WHERE "year">2006 AND "men_s_singles"='cancelled';

Question: Who played Men's singles in 2007?
SQL: SELECT "men_s_singles" FROM "previous_winners" WHERE "year"=2007;