ซีซั่นนี้มีคนกำกับกี่คน?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
How many people directed episode 7 In the season?It is not neccessary to use all the tables.
 table_23937219_3:  (directed_by [ VARCHAR ] season__number [ VARCHAR) ]
SELECT COUNT(directed_by) FROM table_23937219_3 WHERE season__number = 7