user: Question: How many people attended the UEFA Champions League competition?
Columns: ['Competition', 'Attendance', 'Opponent', 'Season', 'Result']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['Welsh Premier League', 2593.0, 'Prestatyn Town', '2011–12', '5–3']
SQL:

assistant: SELECT SUM("Attendance") FROM "Table" WHERE "Competition" = 'UEFA Champions League';