diff --git a/04-databases/basic-blog/CommentRoutines.m b/04-databases/basic-blog/CommentRoutines.m
index 7bf02c2..9561529 100644
--- a/04-databases/basic-blog/CommentRoutines.m
+++ b/04-databases/basic-blog/CommentRoutines.m
@@ -1,18 +1,22 @@
 
-fetch(n,data)
+fetchByComment(idComment,data)
   n record
   k data
-  i n="" q 0
-  s record=$get(^comments(n))
-  s data("description")=$piece(record,"~",1)
-  s data("id_post")=$piece(record,"~",2)
-  q 1
+  i idComment="" q 0
+  s lev1=""
+  s lev2=""
+  f  s lev1=$o(^comments(lev1)) q:lev1=""  d
+  . f  s lev2=$o(^comments(lev1,lev2)) q:lev2=""  d
+  . . i lev1=idComment d
+  . . . s record=$get(^comments(idComment,lev2))
+  . . . s data("description")=$piece(record,"~",1)
+  . . . q
+  q
 
-set(n,data)
-  i n="" q 0
+set(idComment,idPost,data)
+  i idComment=""!idPost="" q 0
   s description=$piece(data,"~",1)
-  s idPost=$piece(data,"~",2)
-  s ^comments(n)=description_"~"_idPost
+  s ^comments(idComment,idPost)=description
   q 1
 
 remove(n)
diff --git a/04-databases/basic-blog/Main.m b/04-databases/basic-blog/Main.m
index b9bc912..bd9f145 100644
--- a/04-databases/basic-blog/Main.m
+++ b/04-databases/basic-blog/Main.m
@@ -2,71 +2,48 @@
 ; create users
 
   s ok=$$set^UserRoutines(1,"alice~password~alice-jones@no-reply.com~Alice Jones")
-  i ok=1 d
-  . w "User successfully created!",!
-  e  d
-  . w "Whoops! The user could not be created.",!
-
   s ok=$$set^UserRoutines(2,"bob~password~bob-smith@no-reply.com~Bob Smith")
-  i ok=1 d
-  . w "User successfully created!",!
-  e  d
-  . w "Whoops! The user could not be created.",!
 
 ; create posts
 
-  s ok=$$set^PostRoutines(1,"lorem-ipsum~Lorem ipsum~Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.~1")
-  i ok=1 d
-  . w "Post successfully created!",!
-  e  d
-  . w "Whoops! The post could not be created.",!
-
-  s ok=$$set^PostRoutines(2,"excepteur-sint-occaecat~Excepteur sint occaecat~Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.~2")
-  i ok=1 d
-  . w "Post successfully created!",!
-  e  d
-  . w "Whoops! The post could not be created.",!
+  s ok=$$set^PostRoutines(1,1,"lorem-ipsum~Lorem ipsum~Lorem ipsum dolor sit amet, consectetuer adipiscing elit.")
+  s ok=$$set^PostRoutines(2,1,"donec-pede-justo~Donec pede justo~Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu.")
+  s ok=$$set^PostRoutines(3,2,"curabitur-ullamcorper-ultricies~Curabitur ullamcorper ultricies~ Curabitur ullamcorper ultricies nisi.")
+  s ok=$$set^PostRoutines(4,2,"donec-vitae-sapien~Donec vitae sapien~Donec vitae sapien ut libero venenatis faucibus. Nullam quis ante.")
 
 ; create comments
 
-  s ok=$$set^CommentRoutines(1,"This is awesome. Thank you.~1")
-  i ok=1 d
-  . w "Comment successfully created!",!
-  e  d
-  . w "Whoops! The comment could not be created.",!
+  s ok=$$set^CommentRoutines(1,1,"This is awesome! Thank you.")
+  s ok=$$set^CommentRoutines(2,2,"Thank you so much for sharing this.")
 
-  s ok=$$set^CommentRoutines(2,"Thank you so much for sharing this.~2")
-  i ok=1 d
-  . w "Comment successfully created!",!
-  e  d
-  . w "Whoops! The comment could not be created.",!
+; fetch posts
 
-; fetch a post
+  do fetchByPost^PostRoutines(1,.data)
+  w "Post fetched:",!
+  w "slug: ",data("slug"),!
+  w "title: ",data("title"),!
+  w "description: ",data("description"),!
 
-  s ok=$$fetch^PostRoutines(1,.data)
-  i ok=1 d
-  . w !,"Post successfully fetched!",!
-  . w "slug: ",data("slug"),!
-  . w "title: ",data("title"),!
-  . w "description: ",data("description"),!
-  . w "id_user: ",data("id_user"),!
-  e  d
-  . w "Whoops! The post could not be fetched.",!
+  do fetchByPost^PostRoutines(2,.data)
+  w !,"Post fetched:",!
+  w "slug: ",data("slug"),!
+  w "title: ",data("title"),!
+  w "description: ",data("description"),!
 
-; fetch a post
+; fetch comments
 
-  s ok=$$fetch^CommentRoutines(2,.data)
-  i ok=1 d
-  . w !,"Comment successfully fetched!",!
-  . w "description: ",data("description"),!
-  . w "id_post: ",data("id_post"),!,!
-  e  d
-  . w "Whoops! The post could not be fetched.",!
+  do fetchByComment^CommentRoutines(1,.data)
+  w !,"Comment fetched:",!
+  w "description: ",data("description"),!
+
+  do fetchByComment^CommentRoutines(2,.data)
+  w !,"Comment fetched:",!
+  w "description: ",data("description"),!
 
 ; drop database
 
   s ok=$$drop^DatabaseRoutines()
   i ok=1 d
-  . w "Database successfully dropped!",!
+  . w !,"Database successfully dropped!",!
   e  d
   . w "Whoops! The database could not be dropped.",!
diff --git a/04-databases/basic-blog/PostRoutines.m b/04-databases/basic-blog/PostRoutines.m
index 9c14e3c..57cfddb 100644
--- a/04-databases/basic-blog/PostRoutines.m
+++ b/04-databases/basic-blog/PostRoutines.m
@@ -1,22 +1,26 @@
 
-fetch(n,data)
+fetchByPost(idPost,data)
   n record
   k data
-  i n="" q 0
-  s record=$get(^posts(n))
-  s data("slug")=$piece(record,"~",1)
-  s data("title")=$piece(record,"~",2)
-  s data("description")=$piece(record,"~",3)
-  s data("id_user")=$piece(record,"~",4)
-  q 1
+  i idPost="" q 0
+  s lev1=""
+  s lev2=""
+  f  s lev1=$o(^posts(lev1)) q:lev1=""  d
+  . f  s lev2=$o(^posts(lev1,lev2)) q:lev2=""  d
+  . . i lev1=idPost d
+  . . . s record=$get(^posts(idPost,lev2))
+  . . . s data("slug")=$piece(record,"~",1)
+  . . . s data("title")=$piece(record,"~",2)
+  . . . s data("description")=$piece(record,"~",3)
+  . . . q
+  q
 
-set(n,data)
-  i n="" q 0
+set(idPost,idUser,data)
+  i idPost=""!idUser="" q 0
   s slug=$piece(data,"~",1)
   s title=$piece(data,"~",2)
   s description=$piece(data,"~",3)
-  s idUser=$piece(data,"~",4)
-  s ^posts(n)=slug_"~"_title_"~"_description_"~"_idUser
+  s ^posts(idPost,idUser)=slug_"~"_title_"~"_description
   q 1
 
 remove(n)