user: Question: Who won the Mixed doubles when Juliane Schenk won the Women's Singles?
Columns: ['Year', "Men's singles", "Women's singles", "Men's doubles", "Women's doubles", 'Mixed doubles']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1990', 'Morten Frost Hansen', 'Pernille Nedergaard', 'Imay Hendra Bagus Setiadi', 'Christine Magnusson Maria Bengtsson', 'Thomas Lund Pernille Dupont']
SQL:

assistant: SELECT "Mixed doubles" FROM "Table" WHERE "Women's singles" = 'Juliane Schenk';