CREATE TABLE table_name_18 (podiums NUMBER, class VARCHAR2, f_laps VARCHAR2)

How many Podiums have a Class of 250cc, and an F laps of 0?
SELECT SUM(podiums) FROM table_name_18 WHERE class = "250cc" AND f_laps = 0
SELECT SUM("podiums") FROM "table_name_18" WHERE "250cc" = "class" AND "f_laps" = 0