CREATE TABLE "singles_champions" (
  "location" text,
  "year" real,
  "champion" text,
  "runner_up" text,
  "score" text
);

Question: What year weas John McEnroe the champion?
SQL: SELECT AVG("year") FROM "singles_champions" WHERE "champion"='john mcenroe';

Question: Who was the runner-up, when the champion was Björn Borg after 1978?
SQL: SELECT "runner_up" FROM "singles_champions" WHERE "champion"='björn borg' AND "year">1978;

Question: Who was the champion earlier than 1978 when the runner-up was Jimmy Connors?
SQL: SELECT "champion" FROM "singles_champions" WHERE "runner_up"='jimmy connors' AND "year"<1978;