user: Question: What is the City, when the Winner is Ruben Visser?
Columns: ['Date', 'City', 'Event', 'Winner', 'Prize']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['19-25 August 2012', 'Barcelona', 'EPT Barcelona', 'Mikalai Pobal', '€1,007,550']
SQL:

assistant: SELECT "City" FROM "Table" WHERE "Winner" = 'Ruben Visser';