Alain Prost ขับกริดตัวไหน?ไม่จำเป็นต้องใช้ทุกโต๊ะ
Which Grid did Alain Prost drive on?It is not neccessary to use all the tables.
 table_name_39:  (grid [ INTEGER ] driver [ VARCHAR) ]
SELECT SUM(grid) FROM table_name_39 WHERE driver = "alain prost"