collection: auto merge join conditions for the same table (alias) [refs

#541]

src/Collection/Functions/JunctionFunctionTrait.php

@@ -5,8 +5,11 @@
 
 use Nextras\Dbal\QueryBuilder\QueryBuilder;
 use Nextras\Orm\Collection\Helpers\DbalExpressionResult;
+use Nextras\Orm\Collection\Helpers\DbalJoinEntry;
 use Nextras\Orm\Collection\Helpers\DbalQueryBuilderHelper;
 use Nextras\Orm\Collection\Helpers\IDbalAggregator;
+use function array_unshift;
+use function count;
 
 
 /**
@@ -43,6 +46,7 @@ protected function normalizeFunctions(array $args): array
 
 	/**
 	 * @param string $dbalModifier either %or or %and dbal modifier
+	 * @param array<int|string, mixed> $args
 	 */
 	protected function processQueryBuilderExpressionWithModifier(
 		string $dbalModifier,
@@ -66,11 +70,52 @@ protected function processQueryBuilderExpressionWithModifier(
 
 		return new DbalExpressionResult(
 			[$dbalModifier, $processedArgs],
-			$joins,
+			$this->rewriteJoins($dbalModifier, $joins),
 			null,
 			$isHavingClause,
 			null,
 			null
 		);
 	}
+
+
+	/**
+	 * @param array<DbalJoinEntry> $joins
+	 * @return array<DbalJoinEntry>
+	 */
+	protected function rewriteJoins(string $dbalModifier, array $joins): array
+	{
+		if (count($joins) === 0) return [];
+
+		/** @var array<array<DbalJoinEntry>> $aggregated */
+		$aggregated = [];
+		foreach ($joins as $join) {
+			$aggregated[$join->toAlias][] = $join;
+		}
+
+		$merged = [];
+		foreach ($aggregated as $sameJoins) {
+			if (count($sameJoins) === 1) {
+				$merged[] = $sameJoins[0];
+			} else {
+				$first = $sameJoins[0];
+				$args = [];
+				foreach ($sameJoins as $sameJoin) {
+					$joinArgs = $sameJoin->onArgs;
+					array_unshift($joinArgs, $sameJoin->onExpression);
+					$args[] = $joinArgs;
+				}
+				$merged[] = new DbalJoinEntry(
+					$first->toExpression,
+					$first->toArgs,
+					$first->toAlias,
+					$dbalModifier,
+					[$args],
+					$first->conventions
+				);
+			}
+		}
+
+		return $merged;
+	}
 }

tests/cases/integration/Relationships/relationships.manyHasMany.phpt

@@ -7,6 +7,7 @@
 
 namespace NextrasTests\Orm\Integration\Relationships;
 
+
 use Nextras\Dbal\IConnection;
 use Nextras\Orm\Collection\ICollection;
 use Nextras\Orm\Relationships\HasMany;

tests/cases/integration/Relationships/relationships.oneHasMany.phpt

@@ -337,6 +337,19 @@ class RelationshipOneHasManyTest extends DataTestCase
 		]);
 		Assert::same(1, $books->countStored());
 	}
+
+
+	public function testSameTableJoinWithImplicitAggregation(): void
+	{
+		$books = $this->orm->books->findBy([
+			ICollection::OR,
+			['tags->id' => [1]],
+			['tags->id' => null], // no match
+		]);
+
+		Assert::same(1, $books->countStored());
+		Assert::same(1, $books->count());
+	}
 }