user: Question: Which driver won when the winning constructor was Bugatti at the Boulogne Grand Prix ?
Columns: ['Name', 'Circuit', 'Date', 'Winning driver', 'Winning constructor', 'Report']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Pozzo Circuit', 'Verona', '21 March', 'Alessandro Consonno', 'Bugatti', 'Report']
SQL:

assistant: SELECT "Winning driver" FROM "Table" WHERE "Winning constructor" = 'Bugatti' AND "Name" = 'Boulogne Grand Prix';