perfect test

aerich/ddl/postgres/__init__.py

@@ -0,0 +1,8 @@
+from tortoise.backends.asyncpg.schema_generator import AsyncpgSchemaGenerator
+
+from aerich.ddl import BaseDDL
+
+
+class PostgresDDL(BaseDDL):
+    schema_generator_cls = AsyncpgSchemaGenerator
+    DIALECT = AsyncpgSchemaGenerator.DIALECT

aerich/ddl/sqlite/__init__.py

@@ -0,0 +1,8 @@
+from tortoise.backends.sqlite.schema_generator import SqliteSchemaGenerator
+
+from aerich.ddl import BaseDDL
+
+
+class SqliteDDL(BaseDDL):
+    schema_generator_cls = SqliteSchemaGenerator
+    DIALECT = SqliteSchemaGenerator.DIALECT