CREATE TABLE "previous_winners" (
  "year" real,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text,
  "mixed_doubles" text
);

Question: Who are the mens doubles and womens singles is wang shixian?
SQL: SELECT "mens_doubles" FROM "previous_winners" WHERE "womens_singles"='Wang Shixian';

Question: Who is the mens singles and womens singlses is wang shixian?
SQL: SELECT "mens_singles" FROM "previous_winners" WHERE "womens_singles"='Wang Shixian';

Question: Who are the mens doubles and and mens singles is lee hyun-il?
SQL: SELECT "mens_doubles" FROM "previous_winners" WHERE "mens_singles"='Lee Hyun-il';

Question: Who are the mens singles and womens singles with sun yu?
SQL: SELECT "mens_singles" FROM "previous_winners" WHERE "womens_singles"='Sun Yu';