For each staff id, what is the description of the role that is involved with the most number of projects?
return staff id ;return roles of #1 ;return projects of #2 ;return number of  #3 for each #2 ;return #2 where #4 is highest ;return description of #5 for each #1
['select', 'project', 'project', 'group', 'superlative', 'group']