user: Question: Tell me the competition of 20 August 2008
Columns: ['Date', 'Venue', 'Score', 'Result', 'Competition']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['13 October 2002', 'Stade des Martyrs , DR Congo', '1–0', '2–0', '2004 Africa Cup of Nations qualifier']
SQL:

assistant: SELECT "Competition" FROM "Table" WHERE "Date" = '20 August 2008';