user: Question: Who was the opponent when the record recorded was 64-78?
Columns: ['Date', 'Time', 'Opponent', 'Score', 'Loss', 'Attendance', 'Record']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['September 1', '7:05pm', '@ Red Sox', '7 - 4', 'Olson (8-7)', '37,565', '63-74']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Record" = '64-78';