Fixed bug in migrations, if migrations directory doesn't exist in module

src/django_clickhouse/migrations.py

@@ -10,7 +10,7 @@ from django.db import DEFAULT_DB_ALIAS as DJANGO_DEFAULT_DB_ALIAS
 from infi.clickhouse_orm.migrations import MigrationHistory
 from infi.clickhouse_orm.utils import import_submodules
 
-from django_clickhouse.utils import lazy_class_import
+from django_clickhouse.utils import lazy_class_import, module_exists
 from .configuration import config
 from .database import connections
 
@@ -49,6 +49,7 @@ def migrate_app(app_label, db_alias, up_to=9999):
     db = connections[db_alias]
     migrations_package = "%s.%s" % (app_label, config.MIGRATIONS_PACKAGE)
 
+    if module_exists(migrations_package):
         applied_migrations = db._get_applied_migrations(migrations_package)
         modules = import_submodules(migrations_package)
 

src/django_clickhouse/utils.py

@@ -4,8 +4,7 @@ from typing import Union, Any, Optional, TypeVar, Set
 import pytz
 import six
 from importlib import import_module
-
+from importlib.util import find_spec
-from infi.clickhouse_orm.database import Database
 
 from .database import connections
 
@@ -53,6 +52,17 @@ def format_datetime(dt, timezone_offset=0, day_end=False, db_alias=None):
     return server_dt.strftime("%Y-%m-%d %H:%M:%S")
 
 
+def module_exists(module_name):  # type: (str) -> bool
+    """
+    Checks if moudle exists
+    :param module_name: Dot-separated module name
+    :return: Boolean
+    """
+    # Python 3.4+
+    spam_spec = find_spec(module_name)
+    return spam_spec is not None
+
+
 def lazy_class_import(obj):  # type: (Union[str, Any]) -> Any
     """
     If string is given, imports object by given module path.