题库调整

app/views/users/question_banks/index.json.jbuilder

@@ -8,7 +8,7 @@ json.question_banks @question_banks do |question_bank|
   json.is_public question_bank.is_public
   json.quotes_count question_bank.quotes
   json.creator_name question_bank.user.name
-  json.course_list_name question_bank.course_list.name
+  json.course_list_name question_bank.course_list&.name
   json.updated_at question_bank.updated_at
   json.solve_count @solve_count_map.fetch(question_bank.id, 0)
 end