user: Question: How large, in square kilometers, is Sackville?
Columns: ['Official Name', 'Status', 'Area km 2', 'Population', 'Census Ranking']
Types: ['text', 'text', 'real', 'real', 'text']
Sample row: ['Moncton', 'City', 141.17, 69074.0, '79 of 5,008']
SQL:

assistant: SELECT "Area km 2" FROM "Table" WHERE "Official Name" = 'Sackville';