'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '

C:\...\lib\site-packages\flask_sqlalchemy\__
init__.py:835: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant over
head and will be disabled by default in the future.  Set it to True or False to suppress t
his warning.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
>>>

修改方法：
flask_sqlalchemy包，init.py下的init_app方法，找到（828-830行）将None改为True