ใครคือผู้สมัครใน districk Pennsylvania 12?ไม่จำเป็นต้องใช้ตารางทั้งหมด
Who were the candidates in districk Pennsylvania 12?It is not neccessary to use all the tables.
 table_2668199_2:  (candidates [ VARCHAR ] district [ VARCHAR) ]
SELECT candidates FROM table_2668199_2 WHERE district = "Pennsylvania 12"