Fixed bug with batched insert_tuple

src/django_clickhouse/database.py

@@ -97,7 +97,8 @@ class Database(InfiDatabase):
             buf = BytesIO()
             query = 'INSERT INTO `%s`.`%s` (%s) FORMAT TabSeparated\n' \
                     % (self.db_name, model_class.table_name(), fields_list)
-            buf.write(query.encode('utf-8'))
+            query_enc = query.encode('utf-8')
+            buf.write(query_enc)
             buf.write(tuple_to_csv(first_tuple).encode('utf-8'))
 
             # Collect lines in batches of batch_size
@@ -112,6 +113,7 @@ class Database(InfiDatabase):
                     yield buf.getvalue()
                     # Start a new batch
                     buf = BytesIO()
+                    buf.write(query_enc)
                     lines = 0
 
             # Return any remaining lines in partial batch

tests/test_database.py

@@ -31,6 +31,22 @@ class CollapsingMergeTreeTest(TestCase):
             'str_field': str(i)
         } for i in range(10)], [item.to_dict() for item in qs])
 
+    def test_insert_tuples_batch_size(self):
+        tuple_class = ClickHouseTestModel.get_tuple_class()
+        data = [
+            tuple_class(id=i, created_date=date.today(), value=i, str_field=str(i))
+            for i in range(10)
+        ]
+        self.db.insert_tuples(ClickHouseTestModel, data, batch_size=2)
+
+        qs = ClickHouseTestModel.objects.order_by('id').all()
+        self.assertListEqual([{
+            'id': i,
+            'created_date': date.today(),
+            'value': i,
+            'str_field': str(i)
+        } for i in range(10)], [item.to_dict() for item in qs])
+
     def test_insert_tuples_special_characters(self):
         tuple_class = ClickHouseTestModel.get_tuple_class()
         data = [tuple_class(id=1, created_date=date.today(), value=1, str_field='\t')]