Gary Muller มีกี่เซ็ต?ไม่จำเป็นต้องใช้ตารางทั้งหมด
How many Sets did Gary Muller have?It is not neccessary to use all the tables.
 table_name_21:  (sets [ VARCHAR ] player [ VARCHAR) ]
SELECT COUNT(sets) FROM table_name_21 WHERE player = "gary muller"