diff --git a/haystack/document_stores/sql.py b/haystack/document_stores/sql.py
index 9a7cd0e28..89a7ab220 100644
--- a/haystack/document_stores/sql.py
+++ b/haystack/document_stores/sql.py
@@ -399,6 +399,8 @@ class SQLDocumentStore(BaseDocumentStore):
             docs_orm = []
             for doc in document_objects[i : i + batch_size]:
                 meta_fields = doc.meta or {}
+                if "classification" in meta_fields:
+                    meta_fields = self._flatten_classification_meta_fields(meta_fields)
                 vector_id = meta_fields.pop("vector_id", None)
                 meta_orms = []
                 for key, value in meta_fields.items():
@@ -785,3 +787,14 @@ class SQLDocumentStore(BaseDocumentStore):
         for whereclause in self._column_windows(q.session, column, windowsize):
             for row in q.filter(whereclause).order_by(column):
                 yield row
+
+    def _flatten_classification_meta_fields(self, meta_fields: dict) -> dict:
+        """
+        Since SQLDocumentStore does not support dictionaries for metadata values,
+        the DocumentClassifier output is flattened
+        """
+        meta_fields["classification.label"] = meta_fields["classification"]["label"]
+        meta_fields["classification.score"] = meta_fields["classification"]["score"]
+        meta_fields["classification.details"] = str(meta_fields["classification"]["details"])
+        del meta_fields["classification"]
+        return meta_fields
diff --git a/test/conftest.py b/test/conftest.py
index b6fcfc3c2..4c8ea3819 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -106,24 +106,6 @@ posthog.disabled = True
 requests_cache.install_cache(urls_expire_after={"huggingface.co": timedelta(hours=1), "*": requests_cache.DO_NOT_CACHE})
 
 
-def _sql_session_rollback(self, attr):
-    """
-    Inject SQLDocumentStore at runtime to do a session rollback each time it is called. This allows to catch
-    errors where an intended operation is still in a transaction, but not committed to the database.
-    """
-    method = object.__getattribute__(self, attr)
-    if callable(method):
-        try:
-            self.session.rollback()
-        except AttributeError:
-            pass
-
-    return method
-
-
-SQLDocumentStore.__getattribute__ = _sql_session_rollback
-
-
 def pytest_collection_modifyitems(config, items):
     # add pytest markers for tests that are not explicitly marked but include some keywords
     name_to_markers = {
diff --git a/test/document_stores/test_document_store.py b/test/document_stores/test_document_store.py
index bd8d1d481..cd8bc4651 100644
--- a/test/document_stores/test_document_store.py
+++ b/test/document_stores/test_document_store.py
@@ -99,7 +99,6 @@ def test_write_with_duplicate_doc_ids_custom_index(document_store: BaseDocumentS
 
 
 def test_get_all_documents_without_filters(document_store_with_docs):
-    print("hey!")
     documents = document_store_with_docs.get_all_documents()
     assert all(isinstance(d, Document) for d in documents)
     assert len(documents) == 5
diff --git a/test/document_stores/test_sql.py b/test/document_stores/test_sql.py
index 8852f28b6..f26153b20 100644
--- a/test/document_stores/test_sql.py
+++ b/test/document_stores/test_sql.py
@@ -62,6 +62,42 @@ class TestSQLDocumentStore(DocumentStoreBaseTestAbstract):
         with pytest.raises(Exception, match=r"(?i)unique"):
             ds.write_documents([doc2], index="index3")
 
+    @pytest.mark.integration
+    def test_sql_get_documents_using_nested_filters_about_classification(self, ds):
+        documents = [
+            Document(
+                content="That's good. I like it.",
+                id="1",
+                meta={
+                    "classification": {
+                        "label": "LABEL_1",
+                        "score": 0.694,
+                        "details": {"LABEL_1": 0.694, "LABEL_0": 0.306},
+                    }
+                },
+            ),
+            Document(
+                content="That's bad. I don't like it.",
+                id="2",
+                meta={
+                    "classification": {
+                        "label": "LABEL_0",
+                        "score": 0.898,
+                        "details": {"LABEL_0": 0.898, "LABEL_1": 0.102},
+                    }
+                },
+            ),
+        ]
+        ds.write_documents(documents)
+
+        assert ds.get_document_count() == 2
+        assert len(ds.get_all_documents(filters={"classification.score": {"$gt": 0.1}})) == 2
+        assert len(ds.get_all_documents(filters={"classification.label": ["LABEL_1", "LABEL_0"]})) == 2
+        assert len(ds.get_all_documents(filters={"classification.score": {"$gt": 0.8}})) == 1
+        assert len(ds.get_all_documents(filters={"classification.label": ["LABEL_1"]})) == 1
+        assert len(ds.get_all_documents(filters={"classification.score": {"$gt": 0.95}})) == 0
+        assert len(ds.get_all_documents(filters={"classification.label": ["LABEL_100"]})) == 0
+
     # NOTE: the SQLDocumentStore behaves differently to the others when filters are applied.
     # While this should be considered a bug, the relative tests are skipped in the meantime