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

Question: Who was the men's single in 1940?
SQL: SELECT "men_s_singles" FROM "canadian_national_championships" WHERE "year"='1940';

Question: Who played women's singles in 1933?
SQL: SELECT "women_s_singles" FROM "canadian_national_championships" WHERE "year"='1933';

Question: Who played mixed doubles when Anna Keir played women's singles?
SQL: SELECT "mixed_doubles" FROM "canadian_national_championships" WHERE "women_s_singles"='anna keir';

Question: In what year did Yvette Porteous play women's singles?
SQL: SELECT "year" FROM "canadian_national_championships" WHERE "women_s_singles"='yvette porteous';