Find the names of the artists who are from Bangladesh and have never received rating higher than 7.
SELECT DISTINCT artist_name FROM artist WHERE country  =  "Bangladesh" EXCEPT SELECT DISTINCT artist_name FROM song WHERE rating  >  7
SELECT DISTINCT artist_name FROM artist WHERE country  =  "Bangladesh" EXCEPT SELECT DISTINCT artist_name FROM song WHERE rating  >  7
[{'artist_name': 'Farida'}, {'artist_name': 'Prity'}]