def fetch_comments(self, criteria):
     return fetch_rows("com", criteria, self._connection)
 def fetch_submissions(self, criteria):
     return fetch_rows("su", criteria, self._connection)
 def fetch_assignments(self, criteria):
     return fetch_rows("as", criteria, self._connection)
 def fetch_coursestudents(self, criteria):
     return fetch_rows("cs", criteria, self._connection)
 def fetch_students(self, criteria):
     return fetch_rows("st", criteria, self._connection)
 def fetch_instructors(self, criteria):
     return fetch_rows("in", criteria, self._connection)