CREATE TABLE table_204_302 (id NUMBER, "rank" NUMBER, "nation" CLOB, "gold" NUMBER, "silver" NUMBER, "bronze" NUMBER, "total" NUMBER)

which is the only nation to win a gold medal and nothing else ?
SELECT "nation" FROM table_204_302 WHERE "gold" = 1 AND "silver" = 0 AND "bronze" = 0
SELECT "nation" FROM "table_204_302" WHERE "bronze" = 0 AND "gold" = 1 AND "silver" = 0