databasemanager.py 文件源码

def get_sql_alchemy_instance():
        """
        Get sql alchemy instance
        :return:    SQLAlchemy
        :rtype:     flask_sqlalchemy.SQLAlchemy
        """

        if DatabaseManager._sql_alchemy_instance is None:
            DatabaseManager._sql_alchemy_instance = SQLAlchemy()
        return DatabaseManager._sql_alchemy_instance