add workaround for same-named columns in GROUP BY for MySQL

[closes #662]

src/Collection/DbalCollection.php

@@ -5,6 +5,8 @@
 
 use Iterator;
 use Nextras\Dbal\IConnection;
+use Nextras\Dbal\Platforms\Data\Fqn;
+use Nextras\Dbal\Platforms\MySqlPlatform;
 use Nextras\Dbal\QueryBuilder\QueryBuilder;
 use Nextras\Orm\Collection\Expression\ExpressionContext;
 use Nextras\Orm\Collection\Functions\Result\DbalExpressionResult;
@@ -319,6 +321,9 @@ public function getQueryBuilder(): QueryBuilder
 			} else {
 				$this->queryBuilder->andWhere($expression->expression, ...$expression->args);
 			}
+			if ($this->mapper->getDatabasePlatform()->getName() === MySqlPlatform::NAME) {
+				$this->applyGroupByWithSameNamedColumnsWorkaround($this->queryBuilder, $groupBy);
+			}
 			$this->filtering = [];
 		}
 
@@ -400,4 +405,32 @@ protected function getHelper(): DbalQueryBuilderHelper
 
 		return $this->helper;
 	}
+
+
+	/**
+	 * Apply workaround for MySQL that is not able to properly resolve columns when there are more same-named
+	 * columns in the GROUP BY clause, even though they are properly referenced to their tables. Orm workarounds
+	 * this by adding them to the SELECT clause and renames them not to conflict anywhere.
+	 *
+	 * @param list<Fqn> $groupBy
+	 */
+	private function applyGroupByWithSameNamedColumnsWorkaround(QueryBuilder $queryBuilder, array $groupBy): void
+	{
+		$map = [];
+		foreach ($groupBy as $fqn) {
+			if (!isset($map[$fqn->name])) {
+				$map[$fqn->name] = [$fqn];
+			} else {
+				$map[$fqn->name][] = $fqn;
+			}
+		}
+		$i = 0;
+		foreach ($map as $fqns) {
+			if (count($fqns) > 1) {
+				foreach ($fqns as $fqn) {
+					$queryBuilder->addSelect("%column AS __nextras_fix_" . $i++, $fqn); // @phpstan-ignore-line
+				}
+			}
+		}
+	}
 }

tests/cases/integration/Collection/collection.having.phpt

@@ -0,0 +1,36 @@
+<?php declare(strict_types = 1);
+
+/**
+ * @testCase
+ * @dataProvider ../../../databases.ini
+ */
+
+namespace NextrasTests\Orm\Integration\Collection;
+
+
+use Nextras\Orm\Collection\ICollection;
+use NextrasTests\Orm\DataTestCase;
+use Tester\Assert;
+
+
+require_once __DIR__ . '/../../../bootstrap.php';
+
+
+class CollectionHavingTest extends DataTestCase
+{
+	public function testHavingWithSameNamedColumnsInGroupBy(): void
+	{
+		// this is a test especially for MySQL and Orm's workaround
+		$books = $this->orm->books->findBy([
+			ICollection::OR,
+			'tags->id' => 1,
+			'author->name' => 'Writer 1',
+			'publisher->name' => 'Nextras publisher A',
+		]);
+		Assert::same($books->count(), 3);
+	}
+}
+
+
+$test = new CollectionHavingTest();
+$test->run();

tests/sqls/NextrasTests/Orm/Integration/Collection/CollectionHavingTest_testHavingWithSameNamedColumnsInGroupBy.sql

@@ -0,0 +1 @@
+SELECT "books".* FROM "books" AS "books" LEFT JOIN "books_x_tags" AS "books_x_tags" ON ("books"."id" = "books_x_tags"."book_id") LEFT JOIN "tags" AS "tags_any" ON (("books_x_tags"."tag_id" = "tags_any"."id") AND "tags_any"."id" = 1) LEFT JOIN "public"."authors" AS "author" ON ("books"."author_id" = "author"."id") LEFT JOIN "publishers" AS "publisher" ON ("books"."publisher_id" = "publisher"."publisher_id") GROUP BY "books"."id", "author"."name", "publisher"."name" HAVING ((COUNT("tags_any"."id") > 0) OR ("author"."name" = 'Writer 1') OR ("publisher"."name" = 'Nextras publisher A'));