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: When was Windy Hill used as a venue?
SQL: SELECT "date" FROM "round_21" WHERE "venue"='windy hill';

Question: Which home team plays at VFL Park?
SQL: SELECT "home_team" FROM "round_21" WHERE "venue"='vfl park';

Question: Which team plays against Footscray as the home team?
SQL: SELECT "home_team" FROM "round_21" WHERE "away_team"='footscray';