Database: imdb
Question: Who was the director of the movie Joy from 2015 ?
SQL:
SELECT t2.name FROM director AS t2 JOIN directed_by AS t1 ON t2.did  =  t1.did JOIN movie AS t3 ON t3.mid  =  t1.msid WHERE t3.release_year  =  2015 AND t3.title  =  "Joy";