รวมทั้งหมดกี่เหรียญ ?ไม่จำเป็นต้องใช้ทุกโต๊ะครับ
how many total medals were there all together ?It is not neccessary to use all the tables.
 table_204_302:  id [ number]  "rank" [ number]  "nation" [ text]  "gold" [ number]  "silver" [ number]  "bronze" [ number]  "total" [ number] 
SELECT SUM("total") FROM table_204_302