diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 21ab50a..d996750 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -30,6 +30,12 @@ parameters:
 			count: 1
 			path: tests/EntityTest.php
 
+		-
+			message: '#^Parameter \#1 \$row of method Tests\\Support\\Models\\UserModel\:\:insert\(\) expects array\<int\|string, bool\|float\|int\|object\|string\|null\>\|object\|null, array\<string, array\|string\> given\.$#'
+			identifier: argument.type
+			count: 1
+			path: tests/EntityTest.php
+
 		-
 			message: '#^Cannot access property \$country on array\|bool\|float\|int\|object\|string\.$#'
 			identifier: property.nonObject
diff --git a/src/Relation.php b/src/Relation.php
index b33beb2..5caa17d 100644
--- a/src/Relation.php
+++ b/src/Relation.php
@@ -27,7 +27,7 @@ class Relation
     /**
      * @var list<mixed>
      */
-    private array|Entity $data = [];
+    private array|Entity|null $data = [];
 
     public function __construct(
         public readonly RelationTypes $type,
@@ -61,7 +61,7 @@ public function applyConditions(): static
     /**
      * @param list<mixed> $data
      */
-    public function setData(array|Entity $data): static
+    public function setData(array|Entity|null $data): static
     {
         $this->data = $data;
 
@@ -277,7 +277,7 @@ public function filterResult(array|Entity|null $row, string $returnType): array|
 
     public function filterResults(array|Entity $results, string $returnType): array|Entity
     {
-        if ($this->type !== RelationTypes::belongsToMany) {
+        if ($results === [] || $this->type !== RelationTypes::belongsToMany) {
             return $results;
         }
 
diff --git a/src/Traits/HasRelations.php b/src/Traits/HasRelations.php
index d7f2d20..c8c89af 100644
--- a/src/Traits/HasRelations.php
+++ b/src/Traits/HasRelations.php
@@ -302,7 +302,14 @@ protected function relationsAfterInsert(array $eventData): array
         }
 
         foreach ($this->relations as $relationObject) {
-            foreach ($relationObject->getData() as $row) {
+            $data = $relationObject->getData();
+
+            // Skip if data is null or empty - nothing to insert
+            if ($data === [null] || $data === []) {
+                continue;
+            }
+
+            foreach ($data as $row) {
                 $row    = $this->transformDataToArray($row, 'insert');
                 $result = $relationObject->applyWith()->model->insert(array_merge($row, [
                     $relationObject->foreignKey => $eventData[$this->primaryKey],
@@ -349,7 +356,14 @@ protected function relationsAfterUpdate(array $eventData): array
         }
 
         foreach ($this->relations as $relationObject) {
-            foreach ($relationObject->getData() as $row) {
+            $data = $relationObject->getData();
+
+            // Skip if data is null or empty - nothing to update
+            if ($data === [null] || $data === []) {
+                continue;
+            }
+
+            foreach ($data as $row) {
                 $row = $this->transformDataToArray($row, 'insert');
 
                 foreach ($eventData[$this->primaryKey] as $id) {
@@ -432,11 +446,9 @@ protected function getDataForRelationById(int|string $id, Relation $relation, st
 
         $relation->applyWith()->applyRelation($id, $this->primaryKey)->applyConditions();
 
-        $results = in_array($relation->type, [RelationTypes::hasOne, RelationTypes::belongsTo], true) ?
-            $relation->model->first() :
-            $relation->model->findAll();
-
-        return $relation->filterResults($results, $this->tempReturnType);
+        return in_array($relation->type, [RelationTypes::hasOne, RelationTypes::belongsTo], true) ?
+            $relation->filterResult($relation->model->first(), $this->tempReturnType) :
+            $relation->filterResults($relation->model->findAll(), $this->tempReturnType);
     }
 
     /**
diff --git a/tests/EntityTest.php b/tests/EntityTest.php
index 4d4ef69..728fb3a 100644
--- a/tests/EntityTest.php
+++ b/tests/EntityTest.php
@@ -102,4 +102,46 @@ public function testRelationQueriedOnlyOnce()
 
         $this->assertSame($queryCount + 1, $this->queryCount);
     }
+
+    public function testSaveNullRelationOneToOneSkipsInsert()
+    {
+        $model = model(UserModel::class);
+        $data  = [
+            'username'   => 'Test User',
+            'company_id' => '2',
+            'country_id' => '1',
+            'profile'    => null,
+        ];
+
+        $id = $model->with('profile')->insert($data);
+
+        $this->assertIsNumeric($id);
+
+        // Verify user was created but profile was not
+        $user = $model->with('profile')->find($id);
+        $this->assertInstanceOf(User::class, $user);
+        $this->assertSame('Test User', $user->username);
+        $this->assertNull($user->profile);
+    }
+
+    public function testSaveEmptyArrayRelationOneToManySkipsInsert()
+    {
+        $model = model(UserModel::class);
+        $data  = [
+            'username'   => 'Test User',
+            'company_id' => '2',
+            'country_id' => '1',
+            'posts'      => [],
+        ];
+
+        $id = $model->with('posts')->insert($data);
+
+        $this->assertIsNumeric($id);
+
+        // Verify user was created but no posts were created
+        $user = $model->with('posts')->find($id);
+        $this->assertInstanceOf(User::class, $user);
+        $this->assertSame('Test User', $user->username);
+        $this->assertSame([], $user->posts);
+    }
 }