Database: tracking_grants_for_research
Question: What roles did staff members play between '2003-04-19 15:06:20' and '2016-03-15 00:33:18'?
SQL: select role_code from project_staff where date_from  >  '2003-04-19 15:06:20' and date_to  <  '2016-03-15 00:33:18'