พื้นผิวของ French Championships คืออะไร?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
What is the surface of the French Championships?It is not neccessary to use all the tables.
 table_2215159_2:  (surface [ VARCHAR ] championship [ VARCHAR) ]
SELECT surface FROM table_2215159_2 WHERE championship = "French championships"