user: Question: Name the opponent when the field is Mitchel Athletic Complex
Columns: ['Date', 'Opponent', 'Home/Away', 'Field', 'Result']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['May 20', 'Rattlers', 'Home', 'Franklin Field', 'W 12-11']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Field" = 'Mitchel Athletic Complex';