user: Question: what is the highest gold when the rank is 12 for the nation Vietnam?
Columns: ['Rank', 'Nation', 'Gold', 'Silver', 'Bronze', 'Total']
Types: ['text', 'text', 'real', 'real', 'real', 'real']
Sample row: ['1', 'China', 7.0, 4.0, 1.0, 12.0]
SQL:

assistant: SELECT MAX("Gold") FROM "Table" WHERE "Rank" = '12' AND "Nation" = 'Vietnam';