CREATE TABLE table_name_34 (date VARCHAR, winning_constructor VARCHAR, winning_driver VARCHAR)

Which Date has a Winning constructor of fiat and a Winning driver of louis wagner?
SELECT date FROM table_name_34 WHERE winning_constructor = "fiat" AND winning_driver = "louis wagner"
SELECT "date" FROM "table_name_34" WHERE "fiat" = "winning_constructor" AND "louis wagner" = "winning_driver"