user: Question: Area (1930) in 1,000skm 2 of 31.7 has what capital?
Columns: ['s Car plate (starting 1937)', 'Voivodeship or city', 'Capital', 'Area (1930) in 1,000skm 2', 'Population (1931) in 1,000s']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['s Car plate (starting 1937)', 'Voivodeship or city', 'Capital', 'Area (1930) in 1,000skm 2', 'Population (1931) in 1,000s']
SQL:

assistant: SELECT "Capital" FROM "Table" WHERE "Area (1930) in 1,000skm 2" = '31.7';