diff --git a/redash/query_runner/query_results.py b/redash/query_runner/query_results.py
index 5bc0eed29a0..028b7bc2299 100644
--- a/redash/query_runner/query_results.py
+++ b/redash/query_runner/query_results.py
@@ -109,9 +109,12 @@ def flatten(value):
         return json_dumps(value)
     elif isinstance(value, decimal.Decimal):
         return float(value)
-    elif isinstance(value, datetime.timedelta):
+    elif isinstance(value, (datetime.date, datetime.time, datetime.datetime, datetime.timedelta)):
         return str(value)
     else:
+        if logger.isEnabledFor(logging.DEBUG):
+            if not isinstance(value, (type(None), str, float, int, bool)):
+                logger.debug("flatten() found unhandled type: %s", str(type(value)))
         return value
 
 
@@ -134,6 +137,7 @@ def create_table(connection, table_name, query_results):
         column_list=column_list,
         place_holders=",".join(["?"] * len(columns)),
     )
+    logger.debug("INSERT template: %s", insert_template)
 
     for row in query_results["rows"]:
         values = [flatten(row.get(column)) for column in columns]
diff --git a/tests/query_runner/test_query_results.py b/tests/query_runner/test_query_results.py
index 1c7ff70cc87..49ade3e0e79 100644
--- a/tests/query_runner/test_query_results.py
+++ b/tests/query_runner/test_query_results.py
@@ -1,5 +1,6 @@
 import datetime
 import decimal
+import logging
 import sqlite3
 from unittest import TestCase
 
@@ -15,6 +16,7 @@
     extract_query_ids,
     extract_query_params,
     fix_column_name,
+    flatten,
     get_query_results,
     prepare_parameterized_query,
     replace_query_parameters,
@@ -248,3 +250,59 @@ def test_non_cached_query_result(self):
             query_result_data = {"columns": [], "rows": []}
             qr.return_value = (query_result_data, None)
             self.assertEqual(query_result_data, get_query_results(self.factory.user, query.id, False))
+
+
+class TestFlatten(TestCase):
+    def test_flatten_with_string(self):
+        self.assertEqual(flatten("hello"), "hello")
+
+    def test_flatten_with_integer(self):
+        self.assertEqual(flatten(10), 10)
+
+    def test_flatten_with_float(self):
+        self.assertEqual(flatten(10.5), 10.5)
+
+    def test_flatten_with_boolean(self):
+        self.assertEqual(flatten(True), True)
+
+    def test_flatten_with_decimal(self):
+        self.assertEqual(flatten(decimal.Decimal("10.5")), 10.5)
+
+    def test_flatten_with_date(self):
+        date = datetime.date(2021, 1, 1)
+        self.assertEqual(flatten(date), "2021-01-01")
+
+    def test_flatten_with_time(self):
+        time = datetime.time(12, 30)
+        self.assertEqual(flatten(time), "12:30:00")
+
+    def test_flatten_with_datetime(self):
+        datetime_obj = datetime.datetime(2021, 1, 1, 12, 30)
+        self.assertEqual(flatten(datetime_obj), "2021-01-01 12:30:00")
+
+    def test_flatten_with_timedelta(self):
+        timedelta_obj = datetime.timedelta(days=2)
+        self.assertEqual(flatten(timedelta_obj), "2 days, 0:00:00")
+
+    def test_flatten_with_list(self):
+        self.assertEqual(flatten([1, 2, 3]), "[1, 2, 3]")
+
+    def test_flatten_with_dictionary(self):
+        self.assertEqual(flatten({"key": "value"}), '{"key": "value"}')
+
+    def test_flatten_with_none(self):
+        self.assertEqual(flatten(None), None)
+
+    @pytest.fixture(autouse=True)
+    def inject_fixtures(self, caplog):
+        self._caplog = caplog
+
+    def test_flatten_unhandled_type(self):
+        class CustomType:
+            pass
+
+        instance = CustomType()
+        with self._caplog.at_level(logging.DEBUG):
+            result = flatten(instance)
+            self.assertEqual(result, instance)
+            self.assertIn("flatten() found unhandled type: %s" % str(type(instance)), self._caplog.records[0].message)