Flask、concurrent.futures 和 SQLAlchemy - 找不到应用程序

Question

我正在构建一个Flask需要后台进程导致上传到SQLAlchemy数据库的应用程序。

相关片段：

from flask_sqlalchemy import SQLAlchemy

import concurrent.futures

import queue

from models import Upload_Tracks

app = Flask(__name__)

db.init_app(app)

app.config.update(

SQLALCHEMY_DATABASE_URI= "sqlite:///%s" % os.path.join(app.root_path, 'path/to/player.sqlite3'))

q = queue.Queue()

在database.py：

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

在models.py：

def Upload_Tracks(item):

        uri = None

        title = unidecode(item['title'])

        artist = unidecode(item['artist'])

        preview = item['preview']

        energy = item['energy']

        popularity = item['popularity']

        tempo = item['tempo']

        brightness = item['brightness']

        key = item['key']

        image = item['artist_image']

        duration = item['duration']

        loudness = item['loudness']

        valence = item['valence']

        genre = item['genre']

        track = Track(title=title,

                      artist=artist,

                      uri=uri,

                      track_id=None)

        db.session.add(track)

        track.preview = preview

        track.energy = energy

        track.popularity = popularity

        track.tempo = tempo

        track.genre = genre

        track.brightness = brightness

        track.key = key

        track.image = image

        track.duration = duration

        track.loudness = loudness

        track.valence = valence

        db.session.commit()

数据库工作正常，没有线程。但是，当我运行它时，会捕获以下异常：

co/mp3-preview/c0d57fed887ea2dbd7f69c7209adab71671b9e6e?cid=d3b2f7a12362468daa393cf457185973 '} 生成了一个异常：未找到应用程序。在视图函数内工作或推送应用程序上下文。请参阅http://flask-sqlalchemy.pocoo.org/contexts/。

但据我所知，这个过程是在@app.route. 这怎么断章取义了？我该如何解决？