Find the name of the students and their department names sorted by their total credits in ascending order.
return students ;return credits of #1 ;return sum of #2 for each #1 ;return #1 sorted by #3 in  ascending order ;return names of #4 ;return departments of #4 ;return names of #6 ;return #5 ,  #7
['select', 'project', 'group', 'sort', 'project', 'project', 'project', 'union']