user: Question: What's the location of The National event with Kevin Martin winning?
Columns: ['Event', 'Date', 'Location', 'Winning skip', 'Runner-up skip']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Baden Masters', 'Sept. 7-9', 'Baden , Switzerland', 'Brad Gushue', 'Andy Kapp']
SQL:

assistant: SELECT "Location" FROM "Table" WHERE "Winning skip" = 'Kevin Martin' AND "Event" = 'The National';