Callsign ใดมีความถี่ 1300?ไม่จำเป็นต้องใช้ทุกตาราง
What callsign has 1300 as the frequency?It is not neccessary to use all the tables.
 table_name_66:  (callsign [ VARCHAR ] frequency [ VARCHAR) ]
SELECT callsign FROM table_name_66 WHERE frequency = 1300