SQL Disparity

I am adding new information on one of our .csv files on an integration, and the SQL I am using to fetch the data is running as expected on mySQL, but will only populate one single value down the whole column instead of different values according to student subplan information once I run the app engine. All students are getting populated with the same subplan value, which is not correct. Below is my code. I am new to this and I would appreciate some guidance.

  SELECT A.ACAD_PLAN  

 , A.REQ_TERM  

 , B.ACAD_SUB_PLAN  

 FROM PS_ACAD_PLAN A