user: Question: What is the Result of the Battle of Marcellae in 756?
Columns: ['Battle', 'Date', 'Bulgarian Commander', 'Byzantine Commander', 'Result']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Battle of Ongal', '680', 'Asparukh', 'Constantine IV', 'Bulgarian victory']
SQL:

assistant: SELECT "Result" FROM "Table" WHERE "Battle" = 'Battle of Marcellae' AND "Date" = '756';