add constraints and S,SD exportation

__init__.py

@@ -2,4 +2,4 @@ from flask import Flask
 
 app = Flask(__name__, template_folder="templates")
 
-import my_flask_app.main
+from . import main

models/models.py

-from sqlalchemy import ARRAY, BIGINT, BOOLEAN, DOUBLE_PRECISION, FLOAT, INTEGER, JSON, NUMERIC, SMALLINT, TIMESTAMP, UUID, VARCHAR, MetaData, String, create_engine, text, inspect
 from sqlalchemy.types import UserDefinedType
 import re