user: Question: When Collingwood was the home team who was the opposing away team?
Columns: ['Home team', 'Home team score', 'Away team', 'Away team score', 'Venue', 'Crowd', 'Date']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Melbourne', '8.14 (62)', 'Richmond', '12.14 (86)', 'MCG', 25353.0, '6 September 1930']
SQL:

assistant: SELECT "Away team" FROM "Table" WHERE "Home team" = 'Collingwood';