回答編集履歴

1

追記

2019/10/29 09:18

投稿

退会済みユーザー
test CHANGED
@@ -40,6 +40,8 @@
40
40
 
41
41
  ```sql
42
42
 
43
+ // group_concat function is available, if you use mysql
44
+
43
45
  select L.name, count(C.id), group_concat(C.name separator '/') from lessons L
44
46
 
45
47
  left join course_lesson CL on L.id = CL.lesson_id