add database connect config

pkg/persistence/databases/postgresql.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+import pip
+import sqlalchemy.ext.asyncio as sqlalchemy_asyncio
+import sys
+
+from .. import database
+
+
+@database.manager_class('postgresql')
+class PostgreSQLDatabaseManager(database.BaseDatabaseManager):
+    """PostgreSQL database manager"""
+
+    async def initialize(self) -> None:
+
+        # default to PostgreSQL with asyncpg driver
+        try:
+            __import__("asyncpg")
+        except ImportError:
+            print('以下依赖包未安装，将自动安装，请完成后重启程序：')
+            print(
+                'The dependence package asyncpg is missing, it will be installed automatically, please restart the program after completion:'
+            )
+            pip.main(['install', "asyncpg"])
+            print('已自动安装缺失的依赖包 asyncpg ，请重启程序。')
+            print('The missing dependence asyncpg have been installed automatically, please restart the program.')
+            sys.exit(0)
+
+        engine_url = self.ap.instance_config.data['system'].get('database', {}).get('engine_url', 'postgresql+asyncpg://root:***@127.0.0.1:5432/postgres')
+        self.engine = sqlalchemy_asyncio.create_async_engine(engine_url)