From c27b02512f36ac8e90267f9e95e58f839bfc1b5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20B=C3=B6hmer?= <mail@jan-boehmer.de>
Date: Sun, 5 Mar 2023 00:57:01 +0100
Subject: [PATCH] Fixed problem with part tables that the wrong number of parts
 (and therefore pages) were displayed.

This hopefully does not break anything else.
---
 .../Adapters/CustomFetchJoinORMAdapter.php    | 54 +++++++++++++++++++
 src/DataTables/PartsDataTable.php             |  3 +-
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 src/DataTables/Adapters/CustomFetchJoinORMAdapter.php

diff --git a/src/DataTables/Adapters/CustomFetchJoinORMAdapter.php b/src/DataTables/Adapters/CustomFetchJoinORMAdapter.php
new file mode 100644
index 00000000..052e2e28
--- /dev/null
+++ b/src/DataTables/Adapters/CustomFetchJoinORMAdapter.php
@@ -0,0 +1,54 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2023 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\DataTables\Adapters;
+
+use Doctrine\ORM\Query;
+use Doctrine\ORM\QueryBuilder;
+use Doctrine\ORM\Tools\Pagination\Paginator;
+use Omines\DataTablesBundle\Adapter\Doctrine\FetchJoinORMAdapter;
+
+/**
+ * This class is a workaround for a bug (or edge case behavior) in the FetchJoinORMAdapter or better the used Paginator
+ * and CountOutputWalker.
+ * If the query contains multiple GROUP BY clauses, the result of the count query is wrong, as some lines are counted
+ * multiple times. This is because the CountOutputWalker does not use DISTINCT in the count query, if it contains a GROUP BY.
+ *
+ * We work around this by removing the GROUP BY clause from the query, and only adding the first root alias as GROUP BY (the part table).
+ * This way we get the correct count, without breaking the query (we need a GROUP BY for the HAVING clauses).
+ *
+ * As a side effect this also seems to improve the performance of the count query a bit (which makes up a lot of the total query time).
+ */
+class CustomFetchJoinORMAdapter extends FetchJoinORMAdapter
+{
+    public function getCount(QueryBuilder $queryBuilder, $identifier)
+    {
+        $qb_without_group_by = clone $queryBuilder;
+
+        //Remove the groupBy clause from the query for the count
+        //And add the root alias as group by, so we can use HAVING clauses
+        $qb_without_group_by->resetDQLPart('groupBy');
+        $qb_without_group_by->addGroupBy($queryBuilder->getRootAliases()[0]);
+
+        $paginator = new Paginator($qb_without_group_by);
+
+        return $paginator->count();
+    }
+}
\ No newline at end of file
diff --git a/src/DataTables/PartsDataTable.php b/src/DataTables/PartsDataTable.php
index d67ed0db..beb050bd 100644
--- a/src/DataTables/PartsDataTable.php
+++ b/src/DataTables/PartsDataTable.php
@@ -22,6 +22,7 @@ declare(strict_types=1);
 
 namespace App\DataTables;
 
+use App\DataTables\Adapters\CustomFetchJoinORMAdapter;
 use App\DataTables\Column\EntityColumn;
 use App\DataTables\Column\IconLinkColumn;
 use App\DataTables\Column\LocaleDateTimeColumn;
@@ -281,7 +282,7 @@ final class PartsDataTable implements DataTableTypeInterface
             ])
 
             ->addOrderBy('name')
-            ->createAdapter(FetchJoinORMAdapter::class, [
+            ->createAdapter(CustomFetchJoinORMAdapter::class, [
                 'simple_total_query' => true,
                 'query' => function (QueryBuilder $builder): void {
                     $this->getQuery($builder);