首次完成数据库登录，注册验证。首次完成，migrate_manager.py迁移多个数据库

app/model/db.py

@@ -0,0 +1,13 @@
+from sqlalchemy.orm import DeclarativeBase
+from flask_sqlalchemy import SQLAlchemy
+from sqlalchemy import MetaData
+class DataBase(DeclarativeBase):
+    meta = MetaData(naming_convention={
+        "ix": "ix_%(column_0_label)s",
+        "uq": "uq_%(table_name)s_%(column_0_name)s",
+        "ck": "ck_%(table_name)s_%(column_0_name)s",
+        "fk": "fk_%(table_name)s_%(column_0_name)s",
+        "pk": "pk_%(table_name)s"
+    })
+
+db = SQLAlchemy()