From 66d49a3f76728945a0b8221bbcc6c54612967b9c Mon Sep 17 00:00:00 2001
From: Matthias Andreas Benkard <code@mail.matthias.benkard.de>
Date: Tue, 29 Aug 2023 16:24:32 +0200
Subject: Fetch comments separately.

This avoids in-memory fetch limit application.

Change-Id: I37535d4e085a8be6602e45fe4a96df2b36176fd7
---
 src/main/java/eu/mulk/mulkcms2/benki/posts/Post.java | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/main/java/eu/mulk/mulkcms2/benki/posts/Post.java b/src/main/java/eu/mulk/mulkcms2/benki/posts/Post.java
index b0aa615..d522b1a 100644
--- a/src/main/java/eu/mulk/mulkcms2/benki/posts/Post.java
+++ b/src/main/java/eu/mulk/mulkcms2/benki/posts/Post.java
@@ -222,9 +222,6 @@ public abstract class Post<Text extends PostText<?>> extends PanacheEntityBase {
 
     cb = cb.where("post.scope").eq(Scope.top_level);
 
-    cb = cb.leftJoinFetch("post.comments", "comment");
-    cb = cb.fetch("comment.texts");
-
     return cb;
   }
 
@@ -373,8 +370,9 @@ public abstract class Post<Text extends PostText<?>> extends PanacheEntityBase {
       }
     }
 
-    // Fetch texts (to avoid n+1 selects).
+    // Fetch texts and comments (to avoid n+1 selects).
     fetchTexts(forwardResults);
+    fetchComments(forwardResults);
 
     return new PostPage<>(prevCursor, cursor, nextCursor, forwardResults);
   }
@@ -388,6 +386,15 @@ public abstract class Post<Text extends PostText<?>> extends PanacheEntityBase {
     }
   }
 
+  public static <T extends Post<?>> void fetchComments(Collection<T> posts) {
+    var postIds = posts.stream().map(x -> x.id).collect(toList());
+
+    if (!postIds.isEmpty()) {
+      find("SELECT p FROM Post p LEFT JOIN FETCH p.comments WHERE p.id IN (?1)", postIds).stream()
+          .count();
+    }
+  }
+
   @CheckForNull
   public Text getText() {
     var texts = getTexts();
-- 
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