CREATE TABLE "round_21" (
  "home_team" text,
  "home_team_score" text,
  "away_team" text,
  "away_team_score" text,
  "venue" text,
  "crowd" real,
  "date" text
);

Question: Who was the away team at the game played at Lake Oval?
SQL: SELECT "away_team" FROM "round_21" WHERE "venue"='lake oval';

Question: Where was the game played that had an away team score of 20.17 (137)?
SQL: SELECT "venue" FROM "round_21" WHERE "away_team_score"='20.17 (137)';

Question: What was the home team score for the game played against Collingwood?
SQL: SELECT "home_team_score" FROM "round_21" WHERE "away_team"='collingwood';

Question: Who was the team with the smallest crowd at the Princes Park venue?
SQL: SELECT MIN("crowd") FROM "round_21" WHERE "venue"='princes park';