School/Club Team East ฤดูกาลใดที่ได้มาโดยการแลกเปลี่ยน?ไม่จำเป็นต้องใช้ตารางทั้งหมด
What season did School/Club Team East have an Acquisition via of trade?It is not neccessary to use all the tables.
 table_name_19:  (season [ VARCHAR ] acquisition_via [ VARCHAR ] school_club_team [ VARCHAR) ]
SELECT season FROM table_name_19 WHERE acquisition_via = "trade" AND school_club_team = "east"