diff --git a/superset/connectors/druid/models.py b/superset/connectors/druid/models.py
index 57038097b7d1..ab2af88d0f45 100644
--- a/superset/connectors/druid/models.py
+++ b/superset/connectors/druid/models.py
@@ -1237,15 +1237,21 @@ def query(self, query_obj):
 
         # Reordering columns
         cols = []
+        groupby = query_obj.get('groupby') or []
+        columns = query_obj.get('columns') or []
+        metrics = query_obj.get('metrics') or []
         if DTTM_ALIAS in df.columns:
             cols += [DTTM_ALIAS]
-        cols += query_obj.get('groupby') or []
-        cols += query_obj.get('columns') or []
-        cols += query_obj.get('metrics') or []
+        cols += groupby
+        cols += columns
+        cols += metrics
 
         cols = [col for col in cols if col in df.columns]
         df = df[cols]
 
+        for col in groupby + columns:
+            df[col] = df[col].astype('str')
+
         time_offset = DruidDatasource.time_offset(query_obj['granularity'])
 
         def increment_timestamp(ts):
diff --git a/tests/druid_tests.py b/tests/druid_tests.py
index c280da790a29..209512bc9222 100644
--- a/tests/druid_tests.py
+++ b/tests/druid_tests.py
@@ -55,6 +55,7 @@ def __reduce__(self):
         'timestamp': '2012-01-01T00:00:00.000Z',
         'event': {
             'dim1': 'Canada',
+            'dim2': 0,
             'metric1': 12345678,
         },
     },
@@ -63,6 +64,7 @@ def __reduce__(self):
         'timestamp': '2012-01-01T00:00:00.000Z',
         'event': {
             'dim1': 'USA',
+            'dim2': 'false',
             'metric1': 12345678 / 2,
         },
     },
@@ -152,7 +154,7 @@ def test_client(self, PyDruid):
             'row_limit': 5000,
             'include_search': 'false',
             'metrics': ['count'],
-            'groupby': ['dim1', 'dim2d'],
+            'groupby': ['dim1', 'dim2'],
             'force': 'true',
         }
         # two groupby
@@ -162,6 +164,7 @@ def test_client(self, PyDruid):
         )
         resp = self.get_json_resp(url)
         self.assertEqual('Canada', resp['data']['records'][0]['dim1'])
+        self.assertEqual('0', resp['data']['records'][0]['dim2'])
 
     def test_druid_sync_from_config(self):
         CLUSTER_NAME = 'new_druid'