user: Question: What is the least silver that has mexico as a nation and a gold less than 0?
Columns: ['Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['text', 'real', 'real', 'real', 'real']
Sample row: ['United States', 8.0, 6.0, 3.0, 17.0]
SQL:

assistant: SELECT MIN("Silver") FROM "Table" WHERE "Nation" = 'mexico' AND "Gold" < 0.0;